Waste magnetite

Electrochemical reduction in aqueous acid is useful in the treatment of waste liquors obtained from the formation of chloroacetic acid by chlorination of acetic acid. The liquors contain further chlorination products. These are reduced in an undivided cell at a magnetite cathode and a carbon anode to give excellent conversion to monochloroacetic acid [73]. 

These results show that technetium can be contained by magnetite in the geosphere, provided reducing conditions can be maintained. This can be aided, for example, by the incorporation of iron or iron oxides in the buffer and backfill materials in the waste disposal vault. 

When the crushed ore is placed in this medium, the potassium values are floated off, and the contaminating sodium values sink and are drawn off and rejected from the bottom of the flotation vessel. Entrapped magnetite from both the product and waste streams is easily recovered magnetically and returned to the flotation vessel. 

Lead, lead oxide, leather wastes, LD-dust, lignite, lime, limestone, lithium carbonate, lithium fluoride, lithium hydroxide Magnesia, magnesium carbonates, magnetite, maleic anhydrate, manganese dioxide, metal powders, molding compounds, molybdenum, monocalciumphosphate (MCP)... 

Legodi, M.A. de Waal, D. (2007). The preparation of magnetite, goethite, hematite and maghemite of pigment quality from mill scale iron waste. Dyes and Pigments, 74(1), 161-168. doi ... 

Bastnaesite from Bayan Obo is strongly intergrown with other minerals. These are magnetite (Fe304), fluorite (CaF2), hematite (Fe203), and various niobium oxide minerals (Zhang et al. 2002) and are not waste, but are also valuable. They are recovered as by-products. 

V. Subramanian, D.-W. Jeong, W.-B. Han, W.-J. Jang, J.-O. Shim, H.-S. Roh, Ha production from high temperature shift of the simulated waste derived synthesis gas over magnetite catalysts prepared by citric acid assisted direct synthesis method, Int. J. Hydrogen Energy 38 (2013) 8699-8703. 

The KAAP reactor at Ocelot is a full flow converter installed in such a manner that it operates in series with the existing magnetite converter. The reactor is a two-bed radial flow, hot wall design with external insulation. An interchanger is provided to exchange the heat between the feed and effluent of the first bed. The feed to the KAAP reactor contains 15% ammonia. The ammonia concentration is increased to more than 21% at the exit of the KAAP reactor. The addition of a KAAP reactor and a new waste heat boiler to produce MP steam by KAAP reactor effluent has the potential of increasing the capacity of the synloop by 40%. 

The yield of retained fraction in the case of irregularly shaped particles was found to be 1.3-1.5 times that for particles with a rounded shape. In crushing operations, for example, particles of barite, quartz, feldspar, and magnetite form rounded particles, decreasing their adhesion. The wastes from low grades of asbestos contain irregularly shaped mineral dust particles, which adhere to the drum surface and are separated as the retained fraction [137]. 

Chemically prepared PPy can also be processed in various shapes, and especially a wide variety of micro- and nanostructured composites have been prepared. An important amount of work is due to Armes and coworkers, who systematically studied the formation of PPy composites formed by chemical oxidation of pyrrole, essentially by iron salts, in various colloidal solutions. This results into the formation of colloidal suspensions of the host substrate (sihca, polystyrene, silica-coated magnetite, etc.) impregnated with PPy. However, the conductivity of pressed pellets of these composites is low, mostly below 1 S/cm. More recently, a wood saw dust/PPy composite has been reported, and applied to the selective removal of chromium (VI) from waste water. PPy/Mn02 composite (see above) has been shown to be effective for use as an active material in supercapacitors. 

The Sirofloc process removes turbidity (algae, bacteria, colloidal matter) and dissolved coloured material from contaminated underground and surface waters or waste waters by flocculation with reusable magnetite particles (a waste product of some iron processing plants). The magnetite particles from 1 to 10 microns in size have great adsorptive powers and important magnetic... 

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