Kerr-McGee uranium mill

Figure S.6 Principal steps in leaching uranium ore in Kerr-McGee uranium mill.

Amine extraction in the Kerr-McGee mill. As a practical example of the use of organic amines to extract uranium from leach liquors, a description will be given of the solvent extraction section of the Kerr-McGee uranium mill, whose leaching section was described in Sec. 8.5 of this chapter [M3, H4]. The solvent extraction plant consists of two similar circuits process conditions approximating those of one circuit are shown in Fig. 5.9. 

As an example of the acid-leaching, solvent extraction class of uranium-concentration processes, a description will be given of the process used in the large uranium mill of the Kerr-McGee Corporation at Grants, New Mexico. This has been condensed from a 1960 paper by Hazen... 

Leaching operations in the Kerr-McGee mill are described in this section, with reference to Fig. 5.6. Recovery of uranium from leach liquor by solvent extraction with organic amines in the Amex process is to be described in Sec. 8.6. 

The ore processed in the Kerr-McGee mill is primarily a sandstone, with uranium minerals in the material bonding the sand grains. The ore contains about 0.2 w/o UaOg, 0.01 to 0.03 w/o M0O3, and 0.05 to nearly 0.20 w/o VjOs. Uranium and molybdenum are leached and recovered, with uranium recovery exceeding 97 percent. Some vanadium is also leached, but was not being recovered in 1971. The ore also contains acid-soluble calcium minerals, equivalent to from 2 to 5 w/o CaO, which are the principal consumers of sulfuric acid. 

The uranium distribution coefficient decreases with increasing S04 concentration, as shown in Fig. 5.8, owing to reversal of the preceding equilibrium. This permits stripping uranium from the amine by aqueous sulfate solution, as practiced at the Exxon miU, Table 5.19. The Kerr-McGee mill strips with 1.5 M NaQ solution by the reaction... 

Figure 5.9 Amex process for recovering uranium from leach liquor. Conditions approximately those of one circuit of Kerr-McGee mill.

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