@granet: the 'swansea.gov' web address is for Swansea City Council; the online index to 'The Cambrian' newspaper was compiled by the city library. The city library is most unlikely to have any information specifically on the Libiola company. The last known run of copper ore sales records (known as the 'Swansea ticketings') were destroyed when Swansea was bombed during the second world war. Scattered copper ore sales information survives amongst the archives of some of the Welsh copper smelting companies, some was published in The Cambrian newspaper and in the Mining Journal but whether any of these sources mention the Libiola company could only be determined by undertaking a protracted search of these sources.
Relatively few archives of Welsh copper smelting companies survive and none are complete. They are to be mostly found in three archives: the National Library of Wales, the West Glamorgan Archives, and the Richard Burton Archives at Swansea University. Not many of them contain copper ore sales or purchase records for the period that the Libiola company operated I'm afraid, and it would be a matter of luck whether a specific smelting company had bid for, or purchased ore from the Libiola company. It would be necessary to trawl through the records yourself to try and find a mention of the Libiola company I'm afraid. The most promising smelting company records to consider for a search would be the 'copper ore offer' books of the Llanelly Copperworks Company which consists of two huge volumes detailing all ore that the company bid for in the mid nineteenth century; these volumes are within the 'Nevill Manuscripts' at the National Library of Wales. All of the Nevill mss. have been microfilmed.
Regrettably, I'm not aware of any online access to the nineteenth century volumes of the Mining Journal. Very few runs of this journal exist. Some volumes were microfilmed around the 1970s but the company that undertook the filming no longer seems to exist and no one seems to know what happened to the master microfilms. There have been a number of discussions proposing digitising the nineteenth century volumes but as yet this has not occurred due to the enormous cost.
Another title that may contain useful information is 'The Mineral Industry', an annual summary off the world's mining and smelting industries published in New York from 1892 onwards. I checked the first twwo volumes (1892 and 1893) today but there was no mention of the Libiola company. However, as the years passed, this publication became less exclusively focussed on mining in the Americas and increasingly carried useful summaries of companies and mines operating in many other parts of the world. It is however something of a matter of luck whether a specific mine or company is reviewed. The period from the late 1890s to the first world war would be the most promising run of volumes for you to check. Unfortunately this publication does not seem to be available online.
Have you checked company registration records in the Uk National Archives? There's a good online catalogue of holdings. Its something of a matter of luck whether the registration records for a specific company have survived intact or whether the records will have been partly 'weeded' or entirely destroyed but its worth checking. Registration records for defunct companies are in the archival class 'BT31' and BT41'. It is also worth checking 'BT31' and 'BT34' which contain the accounts of liquidators of companies.
Another possibility to check is UK Consular Reports. British consols all around the world compiled frequent reports on trade and on the economy of the regions in which they were based. Sometimes these can contain a lot of detailed information on how specific companies or mines were performing. Most were published by the UK government; online access to all UK government publications is available to major institutions that subscribe to the the relevant online provider (Gale, I think) or on microfilm; otherwise it is necessary to track down one of the few surviving full runs of 'British Parliamentary Papers'. Full runs are only found in the very largest UK libraries.
Two books that you might find useful are: (1) J.Orbach 'A guide to tracing the history of a business', 2nd edition, Philimore & Co Ltd, 2009, and (2) J.Armstrong & S.Jones 'Business documents: their origins, sources and uses in historical research', Mansell Publishing Ltd, London & New York, 1987.