Magnesium oxide economics

Table 21. Worldwide Production and United States Economic Data for Magnesium Oxide ...

Magnesium oxide filter resulted more effective in reducing asbestos fibre concentration. However, further optimization studies should to be undertaken (for example filter bed granulometry, duration of the filter, liquid flow, mechanical and electrical combination in removing asbestos fibres) to justify also economically, the utilization of magnesium oxide filter instead of sand filter. 

Economic Importance Magnesium oxide is, after magnesium carbonate, the industrially most important magnesium compound. Worldwide production in 1995 was ca. 5 10 t, with an additional 1 10 t from seawater and brines. 

Burnett, T.A. Wells, W.L. Conceptual design and economics of and improved magnesium oxide flue gas desulfurization process. In Flue Gas Desulfurization Hudson, Wells, Eds. American Chemical Society Washington, DC, 1982 381 11. 

Conceptual Design and Economics of an Improved Magnesium Oxide Flue Gas Desulfurization Process... 

An improved magnesium oxide (MgO) flue gas desulfurization process and its comparative economics are described. Innovations made include the use of a spray dryer, a cyclic hotwater reheater, and a coal-fired fluidized-bed reactor for regeneration of the MgO absorbent. Several technical concerns with the proposed design are addressed, including fly ash and chloride buildup. The economic evaluation shows the process to have a capital investment of about seven percent less than that of a conventional MgO scrubbing process and a 40 percent smaller annual revenue requirement. Finally, a sensitivity analysis is shown relating annual revenue requirements to the byproduct sulfuric acid price credit. 

The commercial development of PPO started in the 1960s, and the first priority was to find an efficient and low-cost procedure to produce the monomer, namely, DMP. Thus, DMP is obtained from cyclohexanone hence, the reaction of cyclohexanone with formaldehyde at 350 °C in the presence of tricalcium phosphate generates DMP with a reasonable yield [33]. DMP can also be produced by the reaction of phenol with methanol at 350 °C, with magnesium oxide as catalyst [34]. The latter method rendered the manufacture of the polymer economically attractive accordingly, from 1964, its commerciaUzation accelerated. 

At least five procedures for removal of impurities have been described (6) none have been completely successful in removing impurities in an economical way (6). In the best method, active magnesium oxide is mixed rapidly with a solution of the gum heated to almost the boiling temperature (21). The flocculent, brownish precipitate (phenolic compounds and iron salts), which forms almost immediately, is removed quickly by filtration. The almost colorless solution is then drum-dried to produce a white powder that is odorless and has only a slight taste. The... 

The Sorbtech (formerly Sanitech) process is a regenerable, dry sorbent process that reportedly can remove over 90% of the SO2, 10-90% of the NOx, HCl, and much of the residual fine particulate from flue gas. The process, currently under development, uses new, inexpensive sorbents called Mag Sorbents made from magnesium oxide (MgO) and an expanded silicate carrier (vermiculite or perlite). A preliminary economic analysis has indicated a cost of 300— 400 per ton (1982 dollars) of SO2 removed (Nelson and Nelson, 1990). 

The ease of oxidation of magnesium is important in the commercial manufacture of titanium metal. Titanium, when quite pure, shows great promise as a structural metal, but the economics of production have thus far inhibited its use. One of the processes currently used, the Kroll process, involves the reduction of liquid titanium tetrachloride with molten metallic magnesium ... 

The United States and Turkey are the world s largest producers of boron.1 Economically important sources are from the ores rasorite (kernite) and tincal, which are both found in the Mojave Desert of California, with borax being the most important source there. The famous 20-Mule-Team Borax, now a part of chemistry folklore, originates from the time when teams of 20 mules used to haul colemanite from Furnace Creek in Death Valley 166 miles south to Mojave. Elemental boron in its impure form can be obtained by the reduction of the oxide B203 by magnesium, and in the pure form by the reduction of BC13 by hydrogen on hot filaments.1... 

For many industrial-scale operations involving the oxidation or reduction of both inorganic and organic substances, and especially for the production of the more active metals such as sodium, calcium, magnesium, and aluminum, the most cost-effective reducing agent is electrons supplied by an external power source. The two most economically important of these processes are described below. 

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