Trail plant

Figure 13.18 Section of exchange tower of Trail plant.

The Trail plant was started up in 1943 and began producing heavy water in 1944. It was shut down in 1956 because of the high cost of its heavy water compared with that produced by the GS process (Sec. 11). 

Details of the Trail plant have been given by Maloney et al. in [M8]. 

For the Trail plant see Canadian nitrogen fixation, Chemistry and Industry, 48 (1929), 769. The Compagnie Neerlandaise de I Azote, formed in Brussels during 1929, opened the Sluiskil factory. The Dutch State Mines operated the Lutterade factory. 

From Table 7.4 bullion with less than 0.5 per cent sulfur can be achieved as well as slags containing around one per cent lead. However, where slag fuming facilities are available for zinc recovery, low lead levels can be sacrificed for furnace throughput as in the case of the Teck-Cominco owned Trail plant. The lead content of slag will be almost fully recovered with the zinc oxide fume and will be recycled in the form of zinc plant leach residues containing lead as lead sulfate. 

Commercialization of the ammonia process was pioneered by the Consolidated Mining Smelting Company, Ltd. (Cominco), which operated a 3 ton/day sulfur-producing pilot unit at their Trail plant in 1934 and placed a 40-ton/day commercial plant in operation in 1936 (King, 1950). The sulfur dioxide recovered in these early units was reduced to elemental sulfur. Later changes in the market picture made it more economical to use the concentrated sulfur dioxide streams as feed to sulfuric acid plants. Sulfur dioxide-absorption processes using both heat and acid neutralization were developed at Trail. Present operations use the neutralization process. 

The two principal problems of this process are oxidation of sulfur dioxide to form ammonium sulfate and loss of ammonia by vaporization. The oxidation problem can be alleviated by acidifying a portion of the circulating absorbent to release sulfur dioxide and produce anunonium sulfate solution or by carefully controlling the ammonium sulfate concentration in the circulating stream so that the required amount can be removed by a crystallization step. At the Trail plant, the first operation was used because ammonia acidification units were available elsewhere in the plant. Control of the ammonia-vapor-loss problem requires maintenance of minimum temperatures in the absorbers and careful adjustment of solution concentrations. 

At the Trail plant, a quanti of solution equivalent to both the ammonia added and the sulfur dioxide absorbed is continuously withdrawn from the base of the absorbers and... 

The recognition in 1940 that deuterium as heavy water [7789-20-0] has nuclear properties that make it a highly desirable moderator and coolant for nuclear reactors (qv) (8,9) fueled by uranium (qv) of natural isotopic composition stimulated the development of industrial processes for the manufacture of heavy water. Between 1940 and 1945 four heavy water production plants were operated by the United States Government, one in Canada at Trail,... 

British Columbia, and three at the U.S. Army Ordinance Works operated by the DuPont Company at Morgantown, West Virginia Cluldersburg, Alabama and Dana, Indiana. The plant at Trail used chemical exchange between hydrogen gas and steam for the initial isotope separation followed by electrolysis for final concentration. The three plants in the United States used vacuum distillation of water for the initial separation followed by electrolysis. Details of these plants and their operations may be found in the Hterature (10). 

Considerably trailing behind VjOj but only slightly behind CeO is FejOj, which shows an onset temperature for HjS release of approximately 520 C. This means Fe Oj is not expected to be able to adequately catalyze step 3 in the FCCU riser environment because of short contact time [5], even though the temperature at the very bottom of the riser exceeds 530 C. In fact, the result of our pilot plant test of such a catalyst is in agreement with this assessment. Thus, it is quite clear that the onset temperature for HjS release is more critical than the rate of take-off in determining the catalyst efficiency for step 3. 

Cominco [Consolidated Mining Smelting Company] A process for absorbing sulfur dioxide from smelting operations. The sulfur dioxide is absorbed in an aqueous solution of ammonium sulfite regeneration is by acidification with sulfuric acid. The ammonium sulfate byproduct is sold. Operated at the Cominco smelter at Trail, Canada, and at other smelters and sulfuric acid plants in the United States. Licensed by the Olin Mathieson Corporation. The name has been applied also to a lead extraction process. 

The Trail system has shown that it is possible to design and operate a system year-round that treats high concentrations of metals. In Trail, the contaminated water is treated to the degree that from the final holding pond it is used for irrigation of trees to be planted in areas near the smelter. 

The pyrrole ring is widely distributed in nature. It occurs in both terrestrial and marine plants and animals [1-3]. Examples of simple pyrroles include the Pseudomonas metabolite pyrrolnitrin, a recently discovered seabird hexahalogenated bipyrrole [4], and an ant trail pheromone. An illustration of the abundant complex natural pyrroles is konbu acidin A, a sponge metabolite that inhibits cyclin-dependent kinase 4. The enormous reactivity of pyrrole in electrophilic substitution reactions explains the occurrence of more than 100 naturally occurring halogenated pyrroles [2, 3]. 

The ability of olfactory systems to cope with this plenitude of stimuli together with the fact that specific volatile compounds became associated with different plants and animals and different body sites, glands, and metabolites, provided exquisitely sensitive and accurate cues to the identities of places, trails, individuals, prey, predators, mates, social groups, and food. Olfaction permitted the development of a heretofore unparalleled perceptual talent. 

Livestock deaths have generally occurred under conditions in which animals consume large amounts of pods or toxic plants in a brief period of time. Most losses happen when hungry livestock are driven through an area of heavy lupine growth, or are trailed through an area where the grass is covered... 

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