Seemingly positive news from two mining companies has failed to impress investors and the stocks are among the worst performers in a downbeat mining sector.Hochschild Mining has completed the construction of new power lines in Peru and Argentina, which will help the Latin America-focused precious metal miner to maximize operational efficiency and reduce costs. The shares are down 8%.Coal of Africa announced the completion of its coal handling and preparation plant at its Mooiplaats Colliery in Mpumalanga, South Africa; its shares are down 9%.Mining stocks are lower in line with metal prices, which are hurt by concerns over the global economy.Property stocks are recovering after a tough few days last week. Even office space provider Workspace Group, which plunged deeper into the red as a result of property write-downs but traded profitably at the operating level, is higher. Top performing sectors so far todayHousehold Goods 5,453.99 +1.23%Mobile Telecommunications 2,606.70 +0.42%Real Estate 1,587.19 +0.33%Bottom performing sectors so far todayMining 15,110.91 -3.88%Industrial Metals 4,428.96 -2.47%Life Insurance 3,020.57 -2.44%General Industrials 1,671.95 -1.79%Industrial Engineering 2,753.51 -1.48%