1977 Charles .G. Wade US Atlas Powder Company proposed not adding the sensitizer, only 1 on the 6th detonators reliable emulsion explosives detonated. Its main feature is the use of sensitization of hollow glass microspheres.
Thin-walled hollow glass beads from sodium borosilicate material with a special process, closed the tiny sphere, the sphere inside the parcel certain amount of gas, its specific density, low thermal conductivity, low oil absorption, particle size and chemical composition controllable superior performance, which makes it very suitable as emulsion explosives sensitizers.
Hollow glass microspheres uniformly distributed stable formation of numerous tiny bubbles of space in explosives. In the role of external initiation impulse, each bead by adiabatic compression local temperature form burning point, and detonated outside the mechanical energy is focused on those burning point is at a temperature high enough to cause burning and oil phase oxidant the violent exothermic chemical reactions such as decomposition, to detonation.Internal phase emulsion explosive matrix supersaturated solution, the density is large, liquid beads were separated by the film; the Foreign Secretary for the film, the density is relatively small, in the long-term storage in the aqueous phase has a tendency to sink, the oil phase has a floating trend, final lead to breaking. Most of hollow glass microspheres diameter between 10μm to 150 μm, and a matrix of internal phase droplet diameter of 10-1μm to 1μm, Foreign Minister film thickness of 10-3μm to 10-2μm.After addition of cenospheres, nearly one-third of the space of the substrate surface granularity “huge” hollow microspheres occupied surface of each bead around the oil droplets are associated with many closely together. They play the role of care afloat stabilizer.
In summary, hollow glass beads is a multifunctional additive in emulsion explosives.
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Sorter is using gravity separation, sorting consists of three sizes settlement box. In the lower portion of each settling tank, are provided with discharge means, when the gas stream containing fly ash from the intake pipe into the settling tank, since the gas flow passage cross section is increased, the gas flow rate drops quickly, fly ash by itself the force of gravity. Part of the gradual drop in the settling tank, according to the principles and other lower, heavier coarse particles, honeycomb vitreous quartz, mullite, solid beads, iron beads and large particles of carbon particles were mostly settled in the sorter within . There are some small hollow glass beads, beads, etc. Superfine into the air separator.
By the action of the separator is in the gas stream during rotation of the centrifugal force on the particles in the inertia, so that particles are separated out from the gas stream. The main form of cyclone separator group, by sinking down box channel tiny hollow beads into the air separator, sorting through a two-stage cyclone group can most small cenospheres sorting out, the remaining very small amount of ultra-fine beads and finally with the air enters the collector.
Collector terminal sorting apparatus, it is both the purification apparatus is recovered ultrafine microbeads collector. Process uses a pulse bag collector, it is not selected by the separator down the majority of ultrafine beads collected.
Currently, deep-sea exploration and development mainly in diving technology, the use of submersible, underwater robots in the deep sea observation, measurement, sampling, install the necessary instruments and facilities, operations, and other underwater.In order to increase pressure resistance, structural stability dive drag body, diving and underwater robots, and to provide sufficient net buoyancy, people started to develop high-strength solid buoyant material to replace the traditional ball buoyancy and pressure buoyancy tube.High strength solid buoyant material is an important part of modern diving technology, to ensure the buoyancy of submersible, submersible increased payload, reduce its dimensions plays an important role.
When the actual buoyancy material requires long-term immersion in water, the requirements of its water, pressure, corrosion and impact. In particular, for each additional 100m depth in the ocean, the pressure will increase by an object about 10 atmospheres ie 1MPa.Therefore, advanced solid buoyancy material should be both light and strong, that is, in the case of maintaining a low density, a substantial increase in compressive strength, but often reduced density while pressure is also reduced.
Over the years, in order to improve performance and storage stability of detonation of emulsion explosives, and other people in the formulation of emulsion explosives, sensitizer and equipment of various aspects of the research.
Density adjustment is one of the key production of emulsion explosives operational aspects, the choice of density modifiers directly affects the detonation performance and storage stability of emulsion explosives.At present, more commonly used emulsion explosive density modifiers of chemical blowing agent and expanded perlite, the disadvantage of the former is difficult to control the density of explosives, short shelf life, and there aftereffect; the latter vulnerable to its size disadvantage is explosive, strength and limit oil resistance, low detonation performance, short shelf life.The introduction of hollow glass microspheres in the emulsion explosives, to overcome the above drawbacks, greatly improving the performance of explosive detonation and significantly improved storage stability. In other countries, like the United States, Britain, Sweden and Japan and other countries has been the use of hollow glass microspheres as emulsion explosive density modifiers.However, due to expensive imported glass beads in the country has been unable to universal. With the advent of homemade beads, the current domestic production of emulsion explosives plant has been gradually promoting the use of hollow glass beads.In order to increase the detonation sensitivity of the emulsion base, people have proposed adding explosive class sensitizing agents and other organic amine nitrate sensitizer.
In the sky into the sea are indispensable, this little beads naturally become the focus of attention. Prior to the development of the mine hospital market, in full compliance with the international community to provide the technical requirements of the hollow glass beads manufacturers mainly US 3M Company. But the United States for the export of raw materials hollow glass microspheres are strictly limited. Although some units costing tens of millions of domestic production and the introduction of foreign technology and equipment, trying to develop the production of hollow glass beads, but the lack of key technologies, regardless of quality or performance of different specifications, can not be compared with foreign products.
In 2008, the hospital began to explore innovative high performance hollow glass microspheres in cooperation with Chinese Academy of Sciences, 2009 related to the preparation and full production has basically ended.
Because of the higher strength requirements, so diving with solid buoyant material commonly used buoyancy regulating medium and high strength resin composite.Especially in the field of application of the deep sea is a great depth, to ensure buoyancy material has high compressive strength and greater security and reliability, often only use hollow glass microspheres with a polymer composite syntactic foam.At the same time, in order to obtain a low density syntactic foam, improve its buoyancy, volume content of hollow glass microspheres are high, reaching 60 to 70%.Thus, hollow glass microspheres have a significant impact on diving performance benefits of solid materials. It can be said that only the hollow glass microspheres base low density, high strength prepared on order to get a good solid buoyant material.
After 2000 , the abroad and targeted has carried on the related technology development, further broaden the hollow glass microballoon application in the field of high-end products, such as the United States of F117A stealth aircraft has adopted the carbonyl ferrite single core ball; Use the narrow heart glass microballoon filled polymer synthesis of deep-sea high buoyancy material has been applied in submarine.
Production status at home and abroad
Internationally leading technology and the ability to mass production and operation of hollow glass microspheres famous enterprises: American Potters Company, 3M Company, Emerson & Cuming Company, the Belgian company Glaverbel, Pittsburgh Corning Company, Philadephia Quartz Company.
The fly ash hollow glass microspheres franchise businesses have Hargreaves PFA Marketing Ltd, most notably the United States and Belgium Potters company Glaverbel company, they can be mass production of hollow glass beads, high refractive index glass beads and solid beading and so many different series, uses beads products, annual production of 100,000 t or more.Japan, the largest output in Asia, but the Japanese domestic demand for large hollow glass microspheres, still need to import large quantities each year. After 20 years of efforts of scientific research personnel, research and development of hollow glass microspheres has been some progress.
Steel Horse Mine Hospital developed high-performance hollow glass microspheres product has been fully put on the market.
Proportioning cost, because of the large dosage of hollow glass beads are relatively high, can be recycled to become important factors restricting the popularization and application of the glass beads drilling fluid can, and only when the beads for 50 ~ 100%, the recovery of hollow glass microsphere, the cost of drilling fluid can with the cost of conventional water-base drilling fluid.
Belonged to non-newtonian fluid, drilling fluid for non-newtonian fluid, the sedimentation rate related to the rheology, has nothing to do with the density difference between the medium. Based on this principle: recycling glass microsphere, especially in the water-base fluid recycling glass beads, water damage fluid rheological property can be used qualitative methods.In essence, is the drilling fluid from the Newton fluid into the Newtonian fluid. A series of data show that recovery rate and final reduced with increase with the increase of the amount of dilution. This method is applicable at the scene, only will be separated from the solids control equipment of the drilling fluid and completion fluid discharge to prepare a good pool, and then add plenty of water, good beads will be floating on the surface of the water.
Reflective powder Uses
Reflective powder is a production of reflective fabric, reflective film, reflective paint, reflective signs, promotional materials, clothing materials, standards stadium runway, shoes, hats, bags, land and air rescue supplies and other new light functional composites core materials.It has a return-reflective properties and the resulting strong retroreflective effect, no external power supply, can be widely used in roads, ports, mining, fire and other fields. As a security mark, greatly improved the safety and reliability of the user.
Since the thermal conductivity is extremely small, used for various insulation plastic filler; for example lighter components can be used to prepare;It can enhance or improve the water resistance, compressive strength and impact strength; very high specific resistance, and low water absorption, it can be widely used in processing the production of cable insulation material; the low porosity and specific surface area, the beads absorb resin small, so even if a lot of filling, viscosity is not high, good processing properties, processing can reduce power consumption, help to improve productivity;Products have good anti-cracking performance; low oil absorption, especially for soft PVC products production, processing, reduce the amount of plasticizer, or for products containing PTFE piston rings and other special products; product size and stability, due to the micro Pearl isotropic orientation caused not generated in different parts of the problem of inconsistent shrinkage, warping, resolves profile, large injection molding process long-standing problem of distortion;With special optical properties, it can be used as a filler for plastics reflective, luminous paint and the like; products are easy to handle after such as drilling, cutting and polishing and so on. These advantages can be reflected in the molding of the finished product is completed.
Problems with the production of raw materials, grading and other issues, promote the use of hollow glass microspheres speed in the plastics industry has gradually accelerated, and will become the new century plastics industry fillers star.
