Flux material

Nocolok 100 Flux, Material Safety Data Sheet, Alcan Aluminum Corp., Apr. 1986. 

There are two process routes for making steel in the UK today the electric arc furnace and the basic oxygen converter. The latter requires a charge of molten iron, which is produced in blast furnaces. The raw materials for producing molten iron are iron ore, coking coal, and fluxes (materials that help the chemical process) - mainly limestone. 

Flux material used during welding, brazing or braze welding to clean the surfaces of the joint, prevent atmospheric oxidation and to reduce impurities. 

Both the bubble departure frequency / and the number of nucleation centers n are difficult to evaluate. These quantities are known to be dependent on the magnitude of the heat flux, material of construction of the tube, roughness of the inside wall, liquid velocity, and degree of superheat in the liquid elements closest to the tube wall. Koumoutsos et al. (K2) have studied bubble departure in forced-convection boiling, and have formulated an equation for calculating bubble departure size as a function of liquid velocity. 

The addition of a relatively small amount of such substances as soda, potash, or borax, all known as fluxes or fluxing materials, lowers the melting temperature of silica sand from over 1700°C to below 1000°C, a temperature feasible in ancient furnaces (see Textbox 28). 

Borax, another fluxing material, is a mineral (composed of hydrated borate of sodium), which has also been known since antiquity. There seems to be no evidence however that it was used in the past as a flux it served mainly as a mordant, for dyeing textiles. Until the eighteenth century borax was apparently procured only from a lake in Tibet, whence it was exported to the Near East and Europe. Sources of borax in Asia Minor and in Tuscany, Italy, were discovered only in much later times. 

Table 4.2 gives a summary of methods for sample decomposition [36 K)]. Fluxes are particularly important for inorganic materials. The use of fluxes is limited by the reaction of trace elements within the crucibles and by the high blank levels in the fluxing materials themselves. 

According to researchers, limitations of DC arc systems include the corrosive nature of the vitrified material, limitations on salt and water content, and uncertain performance in the destruction of organic wastes. The addition of flux materials may be required to allow the vitrified material to be poured and to allow the final waste form to meet performance goals. Volatile radionuclides and metals may accumulate in the off-gas treatment system. 

EM C Engineering Associates markets the Vitriflux vitrification system for the treatment of hazardous wastes. The vendor claims that the unique feature of this vitrification system is that fluxing material is added to achieve vitrification at relatively low temperatures. Although this technology has only been tested as an ex situ process, the developer claims that in situ treatment is possible. 

Beyond the initial choice of a flux material, successful growth of crystals also requires appropriate choices of growth parameters including ... 

May be reduced to 1 part of blue and 5 parts of fluxing material. The fluxing cf these blues are much varied by manufacturers. 

Slag is the product of reaction between fluxing materials and a refractory furnace lining116... 

A mathematical description of an electrochemical system should take into account species fluxes, material conservation, current flow, electroneutrality, hydrodynamic conditions, and electrode kinetics. While rigorous equations governing the system can frequently be identified, the simultaneous solution of all the equations is not generally feasible. To obtain a solution to the governing equations, we must make a number of approximations. In the previous section we considered the mathematical description of electrode kinetics. In this section we shall assume that the system is mass-transport limited and that electrode kinetics can be ignored. 

MAGRAM A process for extracting magnesium metal from dolomite. Similar to Magnetherm, but uses asbestos as the fluxing material and does not require the use of vacuum. Developed by an... 

To ensure the cleanliness of the ceramic membrane gas filters, the housing typically made of stainless steel should have electropolished internal wetted surfaces and welded parts free of flux materials. In addition, considerations need to be given to the materials of construction for housing (e.g., stainless steel) and seals. 

Exclusive of particles of resinous flux material from can manufacture. 

Whenever silicon nitride is synthesized in the presence of aluminum-containing compounds (frequently used as a flux material in process of growing whiskers), there is a high probability of the formation of /3 -SiA10Ns. Up to two-thirds of the silicon in /3-Si3N4 can be substituted by Al without a change of structure. The /3 -SiAl()N has mechanical and physical properties similar to y3-Si3N4. It is, however, thermodynamically more stable than silicon nitride. 

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