Vanadium products minerals processing

Fig. 1. Generalized flow sheet of minerals processing to vanadium products (1).

E. Hukkanen and H. Walden, The production of vanadium and steel from titanomagaeUetes , IntemattonalJoumal of Mineral Processing, 1985, 1-2(15), 89-102. 

The modem process uses a potassium-sulfate-promoted vanadium(V) oxide catalyst on a silica or kie,selguhr support. The SO2 is obtained either by burning pure sulfur or by roasting sulfide minerals (p. 651) notably iron pyrite, or ores of Cu, Ni and Zn during the production of these metals. On a worldwide basis about 65% of the SO2 comes from the burning of sulfur and some 35% by the roasting of sulfide ores but in some countries (e.g, the UK) over 95% conies from the former. 

Table 9.2-2 summarizes the various methods used for the treatment of direct leaching ores. Typical minerals are listed, and those that can be leached by sonoxidative dissolution (NOX) are indicated. Those requiring oxidants (OX) are also indicated. In some cases preireaiment is required, as in the case of reduction masting of nickel laleriles or vanadium ore which may be subjednd to an oxidative salt roast prior to nonoxidative dissolution. Also indicated in Table 9.2-2 are the typical lixiviants used in the process, the methods used for metal recovery, and the form of the fianl product produced. 

There are two other aspects that should be mentioned here that may directly affect the choice of the milling process. First, the uranium ore often contains other metals that have commercial value, like vanadium or niobium, for example, and their recovery may influence the process selected for uranium recuperation. Second, uranium itself may be a by-product of other processes like gold extraction, niobium, and tantalum production or phosphoric acid manufacture. Thus, recovery of low levels of uranium from phosphates, columbite, or gold-bearing minerals may not be economical in itself, but extracting uranium as a by-product from the waste streams of these operations could be commercially sensible. 

The combustion of fossil fuels, particularly coal, generates large quantities of solid by-product, fly ash, blown out of furnaces with combustion gas. The best way to deal with fly ash is to not make it, but that is not possible for most commonly used combustion processes with fuels other than ashfree natural gas. Petroleum fuels produce much less fly ash than coal, but the petroleum fractions that are burned are the heavier ones containing ash-generating mineral matter. One special case is that of vanadium-rich Venezuelan crude oils that release an ash rich in vanadium oxide. 

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