Johannesburg - Thirty-one former South African miners launched a case against AngloGold Ashanti [JSE:ANG] on Thursday in the Johannesburg High Court, saying they contracted the lung disease silicosis while working in its shafts.The case is separate from a silicosis class action suit filed in August against AngloGold Ashanti, Gold Fields [JSE:GFI] and Harmony Gold Mining Company [JSE:HAR] on behalf of thousands of workers.In yet another case, Anglo American [JSE:AGL] Plc's South African unit will face a hearing next year to determine if it is liable for miners who say they developed the disease when they worked in gold mines it has since sold off."AngloGold patently failed in its legal duty to protect its employees against excessive dust exposure," said Richard Meeran, a partner at UK-based Leigh Day & Co which is representing plaintiffs in both the AngloGold and Anglo American cases."It is high time that Anglo American and AngloGold set about establishing a settlement scheme to alleviate the suffering of the former miners and their families," he said.AngloGold Ashanti spokesperson Alan Fine said: "We haven't at this stage received any papers in connection with this reported action." The company offered no further comment.In all of these cases, including the class action suit, mining companies had declined to comment in detail.Graham Briggs, the chief executive of Harmony, told Reuters earlier this year the issue of silicosis was "a big topic" but he did not think it "class action material".Legal and industry experts have said the different suits, if successful, could cost the industry billions of dollars.The plaintiffs and their lawyers say the men contracted silicosis, which has no known cure, by working in gold mines for many years without adequate protection. The silica dust that causes the disease is inhaled from gold-bearing rocks.The disease causes shortness of breath, a persistent cough and chest pains. It also makes people highly susceptible to tuberculosis, which can kill.* Follow Fin24 on Twitter, Facebook, Google+ and Pinterest.