Metal containers slugs

PPha, pyridine) organic groups (olefines, aromatic derivatives) and also form other derivatives, e.g. halides, hydrides, sulphides, metal cluster compounds Compounds containing clusters of metal atoms linked together by covalent (or co-ordinate) bands, metaldehyde, (C2H40) ( = 4 or 6). A solid crystalline substance, sublimes without melting at I12 1I5" C stable when pure it is readily formed when elhanal is left in the presence of a catalyst at low temperatures, but has unpredictable stability and will revert to the monomer, ft is used for slug control and as a fuel. 

Metal ore bodies may contain several different minerals that are separated into individual concentrates. These may be slurry-transported in the same pipeline by pumping them in separate batches, each separated by a slug of water to prevent contamination [607]. Such batching also allows pipeline flow to be maintained when the mine or separation site temporarily runs out of ore. 

The impact extrusion process is used to produce open-ended collapsible tubes from softer metals such as tin and lead. When aluminium is used, it work-hardens during the forming process and the resultant tubes must be annealed to regain flexibility. Alternatively aluminium tubes may be left in their work-hardened state as rigid containers. Impact extrusion is a particularly useful process to produce containers with a high length to diameter ratio, e.g. up to 7 1. A slug of the metal to be formed is held in a female die and is struck by a punch which has the same form as that of the inside of the ultimate container. Upon impact the metal flows up the outside of the punch. A stripper plate then removes the extruded container on its return stroke. 

Although any parallel sided shape can be produced, the most common shape is cylindrical. The slug to produce a cylindrical tube is a metal disc approximately equal in diameter to the finished tube. The thickness of the disc governs the volume of metal available to form the tube base and wall. The clearance between punch and base of die governs base thickness. Hence a container could, if required, be produced with a thick base and thin wall section. 

The basic extrusion process used for metal collapsible tubes is identical with that used to produce rigid aluminium containers except that the slugs used are rings rather than discs and the female die which holds the slug is shaped so that the metal is forced downwards into the die to form the shoulder and nozzle as well as upwards around the plunger (Figure 10.2). 

U.S. production reactors consisted of a uranium metal slug bonded with aluminum-silicon alloy to an aluminum can. Because of the bond, mechanical decladding was impractical. Chemical decladding consisted in dissolving the aluminum can and the bond in hot, aqueous, 10 w/o sodium hydroxide solution containing about 20 w/o sodium nitrate to prevent evolution of hydrogen. The overall reaction was [B12]... 

Commercially available metals (typically in the form of ingots, rods, slugs, etc.) often contain volatile or gaseous impurities associated with the refining process, which can cause the sample to erupt when using electron-beam evaporation. Thus, while it is possible to purchase vacuum-remelted evaporation slugs (at considerable expense), premelting of any metal, which melts before evaporation, in a separate operation prior to the co-condensation experiment, is advisable. 

One type of reactor uses metal slugs containing uranium enriched from the normal 0.7% U-235 to about 3% U-235. The self-sustaining fission reaction is moderated, or controlled, by adjustable control rods containing substances that slow down and capture some of the neutrons produced. Ordinary water, heavy water, and molten sodium are typical coolants used. Energy obtained from nuclear reactions in the form of heat is used in the production of steam to drive turbines for generating electricity. (See Figure 18.7.)... 

Uranium in metallic contact with the inside of the aluminium container would lead to a reaction which would cause blistering and eventual bursting of the can. To prevent this, both the uranium rod and the inside of the aluminium can were coated with a thin layer of graphite before assembly. A further problem was that contact between the slug of uranium and the can altered due to the differential expansion of the two materials, leading to a reduction in the rate of heat transfer from the slug to the can and the formation of local hot spots . The cartridges were therefore filled with helium to improve the heat transfer. When differential expansion occurred the helium filled the gap and ensured reasonable thermal conductivity. 

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