Lead salt agglomeration

The size distribution of the radioactive debris containing the majority of the fission products may bear little relationship to the size distribution of the environmental soil. Vaporization, agglomeration, condensation, and coagulation will probably lead to particles smaller than and larger than those found in the soil. A striking demonstration of this is found in the size distribution of radioactive debris of a low yield explosion over an alluvial salt bed in Nevada (6). While the mean diameter of the pre-shot soil particles was about 6/, the prompt fallout contained many intensely radioactive particles of 1000/ or greater. 

Resorcinol nitrates readily to the trinitro compound, yellow prisms from water or alcohol, m.p. 175.5°. Styphnic acid is more expensive and less powerful than picric acid. Liouville67 found that styphnic acid exploded in a manometric bomb, at a density of loading of 0.2, gave a pressure of 2260 kilos per sq. cm., whereas picric acid under the same conditions gave a pressure of 2350 kilos per sq. cm. It did not agglomerate to satisfactory pellets under a pressure of 3600 kilos per sq. cm. It is a fairly strong dibasic acid, and its salts are notably more violent explosives than the picrates. Lead styphnate has been used to facilitate the ignition of lead azide in detonators. 

Then, there is the problem of crystal water. These are often salt hydrates, i.e., inorganic crystals with different numbers of water molecules attached to each molecule of the basic molecule. Drying may remove crystal water, which leads to quality problems in the product. Furthermore, crystallization at high temperatures may cause the agglomeration and solidification of the product during storage. 

The traditional approach used to embed iron oxide species into a mesostructured matrix, i.e. the post synthesis impregnation of the preformed porous material with an inorganic precursor like iron nitrate and followed by calcinations, presents a major drawback the inorganic salt tend to be adsorbed on the external surface of the silica, which usually leads to large agglomerates outside the mesopores, thus decreasing the specific advantages of... 

Sol-gel Process Hydrolysis of precursor salts in an aqueous or nonaqueous environment to form a colloidal suspension of precipitates often in the form of hydroxide, oxalate, and carbonate Particle size control By reaction temperature and duration, precursor concentration, pH, surfactant additive, precursor materials, and solvent General attributes Spherical shapes further heat treatment is necessary for the nonoxide precipitates and often leads to severe agglomeration... 

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