Mercury cell diagram

FIGU RE 22.5 General wastewater treatment process flow diagram at a mercury cell plant for the production of chlor-alkali. 

Figure 21.18 shows the mercury cell used in the chlor-aUcali process. The cathode is a liquid mercury pool at the bottom of the cell, and the anode is made of either graphite or titanium coated with platinum. Brine is continuously passed through the cell as shown in the diagram. The electrode reactions are... 

Solubilities and the physicochemical data related to these amalgams are readily available in the literature.62-65 Of these, sodium amalgam is of importance from the operational viewpoint of mercury cells. The phase diagram of sodium amalgam has been well established (see Fig. 10), and there are various compounds of... 

FIGURE 6.4. Electrolysis area flow diagram—Mercury cells. 

Sodium hydrosulfite is still a specialty product of some mercury-cell chlorine plants. As the flow diagram, Fig. 9.77, shows, the source of sulfur is SO2. This is dissolved into a circulating Na2S03 solution to form the bisulfite ... 

FIGURE 10.2.9. Energy flow diagram for mercury cell chlor-alkali process. (The numbers are kWhrton" of chlorine.)... 

A general process description for mercury-cell operations is in Chapter 5 and hence, is not elaborated here. It should be noted that these energy flow diagrams do not take into consideration all the process details and can only provide a general description of the energy flows. 

Schematic diagram of a mercury cell for brine electrolysis. 

Figure 24. Schematic diagram of a brine circulation system in the mercury cell process a) Electrolysis cell b) Anolyte tank c) Vacuum column dechlorinator d) Cooler e) Demister f) Vacuum pump g) Seal tank h) Final dechlorination i) Saturator k) Sodium carbonate tank I) Barium chloride tank m) Brine reactor n) Brine filter o) Slurry agitation tank p) Rotary vacuum filter q) Vacuum pump r) Brine storage tank s) Brine supply tank...

Ultimately, AfG° values must be based on experimental results in many cases, these experimental results are themselves obtained from ° values. Early in the twentieth century, G. N. Lewis conceived of an experimental approach for obtaining standard potentials of the alkali metals. This approach involved using a solvent with which the alkali metals do not react. Ethylamine was the solvent chosen. In the following cell diagram, Na(amalg, 0.206%) represents a solution of 0.206% Na in liquid mercury. 

A diagram of their detector is shown in figure 21. The UV adsorption system consists of a low pressure mercury lamp emitting light at 254 nm and a solid state photo cell with quartz windows allowing the photo cell to respond to light in the UV region. 

Fig Diagram of the Zimm-osmometer (Zimm 1946). A typical diameter for the measuring and reference (solvent cell) capillary is 0.5-1 mm. The closure of the filling tube is a 2-mm metal rod. A mercury seal is used at the top to ensure tightness. 

Figure 17.2 (a) and (b) illustrates the schematic diagram of amperometric titrations with the dropping mercury electrode having a titration-cell and an electric circuit respectively. 

Figure 6.6 shows a schematic diagram of the apparatus required as a working electrode for polarography. Such a set-up is almost universally called a dropping mercury electrode (DME), with the mercury drop being immersed in a cell that is essentially the same as that shown in Figure 6.1. 

Figure 6.6 Schematic representation of a typical dropping-mercury electrode (DME) for polarography, where the DME acts as a working electrode in a cell such as that shown in Figure 6.1. The platinum electrode at the top right of the diagram is needed to give an electrical connection. The rate of mercury flow is altered by adjusting by changing the height h.

Figure 7.2. Schematic diagram of the static mercury vapour apparatus. A Absorption cell B metal support C PTFE tubing D reduction vessel E silicone rubber F magnetic bar G magnetic stirrer H PTFE tubing Iq incident beam intensity I transmitted beam intensity and J exhaust. From [34]...

Fig. 4. Schematic diagram of equipment for the determination of mercury showing (a) tube for reduction with SnCl2 and outgassing of mercury vapour (b) magnesium perchlorate desiccant (c) soda-asbestos and (d) silica-windowed cell to fit in light path of instrument.

The cold vapor technique is used for mercury. This technique involves reducing the mercury to the zero valence state with either sodium borohydride or stannous chloride. The mercury is then swept into a gas cell aligned in the light path of the spectrophotometer, using a stream of nitrogen or air. Fig. 4 shows a diagram of a typical unit. 

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