Mercury cells characteristics

Contrary to the technical synthetic aeid the characteristic feature of the sulphate hydrochloric acid is a higher sulphate content. The content of impurities in synthetic hydrochloric acid depends chiefly on the degree of purity of the absorption water. For the manufacture of pure acids distilled water is used and cooling as well as the absorption of hydrogen chloride vapours takes place in a quartz equipment. Similarly, the hydrogen leaving the mercury cells is first of all thoroughly freed of all mercury. 

Electrolytic Cell Operating Characteristics. Currently the greatest volume of clilorine production is by the diaphragm cell process, followed by that of the mercury cell and then the membrane cell. However, because of the ecological and economic advantages of the membrane process over the other systems, membrane cells are currently favored for new production facilities. The basic characteristics of the three cell processes are shown in Figure 5. 

The largest mercury cells are capable of much higher production rates per cell than the largest commercially available diaphragm cells. Typical operating characteristics are given in Table 8.3. 

Many moulded components are affixed on the rubber-lined surface such as anode sleeves in mercury cells used in caustic soda industry. These moulded components are either made from natural soft or ebonite rubbers or Neoprene rubber compounds. While moulding, the flow characteristics of the rubber compound and shrinkage need to be taken into consideration. Some aspects of mould designs are described next. 

Presently, there are five mercury-cell technologies [70,71] practiced in the world, and their operating characteristics are summarized in Table 5.2. The only technology supplier that is active in optimizing the cell design and the cell operations to achieve negligible mercury emissions is DeNora [72]. 

TABLE 5.2. Operating Characteristics of Modem Mercury Cells... 

First we consider the installation and housing of electrolyzers. We address very briefly the comparative advantages of indoor and outdoor installation of electrolyzers and then turn to the characteristics of buildings and the arrangements appropriate to the various types of cell. A description of some of the design considerations of the cell line working zone, especially those related to electrical safety, follows. Building ventilation is then considered separately, with mercury-cell installations as a special case. 

Mercury Telluride. Compounds of mercury with tellurium have gained importance as semiconductors with appHcations in infrared detection (9) and solar cells (10). The ratio of the components is varied, and other elements such as cadmium, zinc, and indium are added to modify the electronic characteristics. 

Amalgamated zinc powder has been used as the negative material to prevent zinc corrosion and zinc passivation. Recently, from the viewpoint of environmental problems, mercury-free alkaline-manganese batteries were developed by using zinc powder with indium, bismuth and other additives [2-4]. Adding indium to zinc powder is the most effective way to improve the characteristics of the cells [3]. Figure 3 shows the variation in the internal impedance of the cells according to the additive content of the zinc powder. 

In order to describe the geometrical and structural properties of several anode electrodes of the molten carbonate fuel cell (MCFC), a fractal analysis has been applied. Four kinds of the anode electrodes, such as Ni, Ni-Cr (lOwt.%), Ni-NiaAl (7wt.%), Ni-Cr (5wt.%)-NijAl(5wt.%) were prepared [1,2] and their fractal dimensions were evaluated by nitrogen adsorption (fractal FHH equation) and mercury porosimetry. These methods of fractal analysis and the resulting values are discussed and compared with other characteristic methods and the performances as anode of MCFC. 

Binary liquid metal systems were used in liquid-metal magnetohydrodynamic generators and liquid-metal fuel cell systems for which boiling heat transfer characteristics were required. Mori et al. (1970) studied a binary liquid metal of mercury and the eutectic alloy of bismuth and lead flowing through a vertical, alloy steel tube of 2.54-cm (1-in) O.D., which was heated by radiation in an electric furnace. In their experiments, both axial and radial temperature distributions were measured, and the liquid temperature continued to increase when boiling occurred. A radial temperature gradient also existed even away from the thin layer next to the... 

In anodic stripping voltammetry the mercury film and the metal ion to be determined are often co-deposited (called in situ mercury deposition). The thin mercury film has characteristics similar to a thin-layer cell, described in Section 9.10. Additionally, it can be easily used in hydrodynamic systems29. 

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