Deposit Types
The Project’s uranium-vanadium deposits in the Jurassic Salt Wash Member of the Morrison Formation are sandstone-type deposits that fit into the U.S. Department of Energy’s (DOE) classification as defined by Austin and D’Andrea (Mickle and Mathews, 1978) Class 240-sandstone; Subclass 244-nonchannelcontrolled peneconcordant. Any future deep drilling to explore for deposits in the Triassic basal Chinle Formation (Moss Back Member) would fit the DOE classification as Class 240-sandstone; Subclass 243- channel-controlled peneconcordant. These classes are very similar to those of Dahlkamp (1993) Type 4- sandstone; Subtype 4.1-tabular/peneconcordant; Class 4.1.2 (a) Vanadium—Uranium (Salt Wash type) and Class 4.1.3-basal-channel (Chinle type).

The La Sal Trend uranium-vanadium deposits are a similar type to those elsewhere in the Uravan Mineral Belt. The Uravan Mineral Belt was defined by Fisher and Hilpert (1952) as a curved, elongated area in southwestern Colorado where the uranium-vanadium deposits in the Salt Wash Member of the Morrison Formation generally have closer spacing, larger size, and higher grade than those in adjacent areas and the region as a whole. The location and shape of mineralized deposits are largely controlled by the permeability of the host sandstone. Most mineralization is in trends where Top Rim sandstones are thick, usually 40 ft or greater.

The La Sal Trend is a large channel of Top Rim sandstone that trends due ........

The mining of all resources in the La Sal Project have been by conventional underground methods. The nature of the Salt Wash uranium vanadium deposits require a random room and pillar mining configuration. The deposits have irregular shapes and occur within several closespaced, flat or slight-dipping horizons. The mineralization often rolls between horizons. The use of rubber-tired equipment allows the miners to follow the ore easily in the slight dips and to ramp up or down to the other horizons. The deposits are accessed from the surface through long declines at gradients of 8-15%, depending on depth and locations suitable for portal sites, such as the La Sal and Pandora/Snowball mines. Deposits may also be accessed through vertical shafts such as at the Beaver and Energy Queen mines. Depending on ground conditions, the shafts will be lined with concrete or with steel and timber-lagging methods. Most recently, the Beaver Shaft was used for hoisting ore, ventilation, and a secondary escape. It is connected underground to the La Sal mine which provided man and equipment access to the Beaver mine areas. The Salt Wash sandstones are usually quite competent rock and require only moderate ground support. The overlying Brushy Basin mudstones are less competent, so the declines are often supported by square set timber or steel arch and timber lagging, as is the case at the La Sal and Pandora mines. The Salt Wash uranium vanadium deposits are usually thinner than the mining height n ........

Grinding
A front-end loader will transfer the mineralized material from the stockpiles to the Mill through the 20 in. stationary grizzly and into the ore-receiving hopper. The ore is then transferred to the 6 ft by 18 ft diameter semi-autogenous grinding (SAG) mill via a 54 in. wide conveyor belt. Water is added with the ore into the SAG mill where the grinding is accomplished. The SAG mill is operated in closed circuit with vibrating screens. The coarse material, P80 +28 mesh (28 openings per linear inch) is returned to the SAG mill for additional grinding and the P80 -28 mesh portion is pumped to the pulp (wet) storage tanks. The pulp storage tanks are three 35 ft diameter by 35 ft high mechanically agitated tanks. These tanks serve two basic purposes. First, they provide storage capacity for the ore prior to chemical processing; and second, they provide a facility for blending the various types of ore prior to processing.

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