Molten bath processes

In molten bath processes, crushed coal is passed with reacting gases into the liquid bath, where gasification occurs. The ash can become part of the liquid bath or can be separated. The media include liquid iron and liquid sodium carbonate. 

Recently, some novel gasification processes have also been developed, including in situ gasification of coal in the underground seam as well as molten bath processes. The different gasification processes are described in the following sections. 

Rummel Single-Shaft Molten Bath Process... 

Due to the application of the described image processing steps on image sequences up to 1000 images per second, it is possible to determine and to analyse the transport process of several hard particles concerning their location, velocity and acceleration inside the molten bath. 

The previous investigations of hard particle transport processes during laser beam dispersing have shown, that the high speed microfocus radioscopy system is a usable arrangement to observe and analyse the movements, velocities and accelerations of particles inside the molten bath. That possibility was, until now, not given by conventional techniques of process... 

The squares visible in figure 5 represent the position of hard particles at the moment of recording. Therefore the time distance between two video records is about 1,3 ms at a record rate of 750 Hz. With these data it is possible to calculate particle velocity. Figure 8 shows the particle movement in the molten bath caused by flow processes. The particles are captured at the contour of the molten bath and transported into the liquid phase. 

The investigations show that the microfocus high speed radioscopy system is suitable for monitoring the hard particle transport during laser beam dispersing. It is possible to observe and analyse the processes inside the molten bath with the presented test equipment. As a consequence a basis for correlation with the results of a simulation is available. 

The rod resulting from the dip-forming process is substantially oxygen-free because the oxygen content in the molten bath must be controlled at less than 20 ppm. 

The Dilex Process utilises a molten lead bath as transfer medium and is applicable to diflfusion coatings of Cr, Al, Ti, Mo, Ni and Co. Finally, a Japanese fused borate bath process produces carbide coatings (Cr, V, Nb or Ta) on carbon and tool steels. The coatings are wear and corrosion resistant. The TD Process uses this technique. 

Hot Dipped Coatings Major attempts have been made to improve the quality of aluminised steel strip. Requirements on coating thickness and uniformity have been imposed. It is the speed of sheet movement, length of path in the molten bath, temperature and composition of the bath that control the thickness of the intermetallic layer which lies below the aluminium outer surface. The process of intermetallic alloy formation is diffusion controlled, and it is usual that some dissolution of iron into the molten aluminium does occur at a rate, Ac/At, which is given by... 

The Alcoa (Aluminum Company of America) process involves the electrolysis of aluminum chloride which is carried out in a molten bath of the composition 50% sodium chloride, 45% lithium chloride and 5% aluminum chloride, maintained at 700 °C. The Bayer process, which involves the production of pure alumina by the dissolution of bauxite with caustic soda and which has been described in the chapter on hydrometallurgy, must be taken into account while presenting a complete picture of the aluminum extraction flowsheet. It... 

In the secondary production of aluminum, scrap is usually melted in gas- or oil-fired reverberatory furnaces of 14,000 to over 45,000 kg capacities. The furnaces have one or two charging wells separated from the main bath by a refractory wall that permits only molten metal into the main bath. The principal processing of aluminum-base scrap involves the removal of magnesium by treating the molten bath with chlorine or with various fluxes such as aluminum chloride, aluminum fluoride,... 

Hot dip coating is the process of coating a metallic workpiece with another metal by immersion in a molten bath to provide a protective him. Galvanizing (hot dip zinc) is the most common hot dip coating. 

The KTP chips are individually immersed in a molten bath of a mixture of RbNOs and Ba(N03)2. Within this bath, the Rb ions diffuse into the unmasked portions of the KTP chip, while the K ions diffuse out of the substrate and into the bath, shown in the illustration in figure 6. In the diffused regions, the rubidium ions increase the index of refraction relative to the undiffused KTP and thus form the optical waveguide. Note that due to the presence of barium, there is an increase in the index of refraction and the ferroelectric domain in the diffused region is reversed and hence the term chemical poling is used for this process. 

Molten-Iron Pure Gas (MIP) and Klockner Molten Iron Processes. This concept is being developed in a joint effort by Sumitomo Metal (Japan) and Klockner (Germany). Coal is gasified with oxygen in a lop- or bottom-blown liquid iron bath. The process accomplishes desulfurization ami particulate removal in one step. 

PROTECTIVE COATING. A film or thin layer of metal glass of paint applied to a substrate primarily to inhibit corrosion, and secondarily for decorative purposes, Metals such as nickel, chromium, copper, and tin are electrodeposited on the base metal paints may be sprayed or brushed on. Vitreous enamel coatings are also used these require baking. Zinc coating are applied by continuous bath process in which a strip of ferrous metal is passed through molten zinc. 

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