I may give this a bit of a go (Yay! Geology!).

First, a clarification: when dealing with metals, these usually occur either in native form, or bound in minerals. Native metals are usable "as is" and require no refining, smelting or chemical processing. Examples are some surficial copper deposits in Michigan and Nunavut (think of the Copper Inuit, for instance), bog iron and native gold. Native metal occurrences tend to be relatively small by modern ore deposit standards. Native Uranium has never been encountered, and given it's chemical behaviour is very unlikely.

Most metals are bound in minerals which have to be physically extracted and concentrated, and then chemically modified to release the metal you're after. Not only does this requires a certain degree of sophistication, but some classes of minerals are more difficult to process as ore sources than others. For instance, sulphides are relatively easy to use as ore, and have been for a variety of deposits including quite ancient ones (Cyprus, Potosi, Neves-Corvo). Just heat them up in a fire with plenty of free flowing oxygen and they'll dissociate into sulphuric acid (which is carried away in fumes) and metal (which will flow to the bottom of your smelter/crucible/whatever).

Which brings us to uranium minerals. There is a wide variety of such minerals. The most abundant uranium minerals are oxydes (pechblende, uraninite, etc). Oxydes are much more difficult to process by artisanal means, needing amongst other things higher températures, and require a more sophisticated understanding and technical capabilities. To my knowledge, there was no extraction of metallic uranium prior to the discovery of Uranium by Martin Klaproth in 1789 (see: Klaproth, M. H. (1789). "Chemische Untersuchung des Uranits, einer neuentdeckten metallische Substanz". Chem. Ann. Freunde Naturl. (2): 387–403.)

So as far as understanding uranium minerals as a source of some kind of metal, Uranium would not have been of much interest prior to the 16^th century. We are far, here, from "ancient civilisations".

Prior to that, any use of uranium would have had to be through the use of its mineral and not as a metal. Uranium phosphates are bright red, orange and yellow, while the oxydes are generally black. They would have been used as mineral dyes (say as a glaze on ceramics), but certainly not as a source of metal. I believe there has been at least one instance where glass in roman mozaics was found to contain quite a lot of Uranium (about 1.25%). Whether this was a deliberate and knowledgeable use of uranium minerals as pigments or if the uranium "just was along for the ride" in a mix of mineral pigments remains to be determined (see: Guenther, R. T., 1911/1912, A Mural Glass Mosaic from the Imperial Roman Villa near Naples, with a Note on the Analysis of the Green and Blue Glass by J. J. Manley, Archaeologia or Miscellaneous Tracts Relating to Antiquity 63, pp. 99-108.) Such use would certainly not require seeing Uranium as anything special, but simply noting that some peculiar bright minerals had attractive colors and throwing them in paint, glazes or other materials for coloring.