Green desire

High purity 75% ferrosihcon containing low aluminum and calcium can be used in continuously cast heats where nozzle blockage is a problem. In iron melting, this ahoy is desirable to minimize buildup on refractory faces in the furnace or on stopper rods or nozzles. Low aluminum ferroshicons can also help reduce hydrogen pin holes in castings poured in green-sand molds. 

Fermentation. The term fermentation arose from the misconception that black tea production is a microbial process (73). The conversion of green leaf to black tea was recognized as an oxidative process initiated by tea—enzyme catalysis circa 1901 (74). The process, which starts at the onset of maceration, is allowed to continue under ambient conditions. Leaf temperature is maintained at less than 25—30°C as lower (15—25°C) temperatures improve flavor (75). Temperature control and air diffusion are faciUtated by distributing macerated leaf in layers 5—8 cm deep on the factory floor, but more often on racked trays in a fermentation room maintained at a high rh and at the lowest feasible temperature. Depending on the nature of the leaf, the maceration techniques, the ambient temperature, and the style of tea desired, the fermentation time can vary from 45 min to 3 h. More highly controlled systems depend on the timed conveyance of macerated leaf on mesh belts for forced-air circulation. If the system is enclosed, humidity and temperature control are improved (76). 

Bayberry Wax. Bayberry wax [8038-77-5] is removed from the surface of the berry of the bayberry (myrtle) shmb by boiling the berries in water and skimming the wax from the surface of the water. The wax is green and made up primarily of lauric, myristic, and palmitic acid esters. The wax has a melting point of 45°C, an acid number of 15, a saponification number of 220, and an iodine number of 6. The wax has an aromatic odor and is used primarily in the manufacture of candles and other products where the distinctive odor is desirable. 

The thickness of the tape is controUed by the sHp characteristics, the height of the doctor blade, the casting rate, and the pressure head of the sHp reservoir behind the doctor blade. SHp viscosities in the range of 1 5 Pa-s (10—50 P) are used to cast tapes at 5—100 cm/s. To achieve the desired strength and flexibUity in the green tape, tape casting slurries contain more binder than those used in sHp casting, as weU as a plasticizer to ensure flexibUity. 

Uniformity and Reproducibility. For most ceramic pigments rapid, uniform, and reproducible conversion to the desired product requires great care in production (40). Adjustment of each lot to standard, using toners, is usually required. The Victoria green garnet, the manganese alumina pink comndum, and the chrome—tin pink sphene are noteworthy for their difficulty in making reproducible product. 

Initially a gummy green precipitate is formed which is difficult to stir magnetically. Eventually, however, the inorganic by-products become more fluid. The use of a mechanical stirrer may be desirable. 

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