(MB) Base metals prices on the Shanghai Futures Exchange were mostly lower during Asian morning trading on Tuesday, with only tin prices in positive territory. Rio Tinto has released its fourth-quarter production results for the three months ended December 31. Vedanta subsidiary Sterlite Copper has hired Felipe Williams as director of business development to be based in the Chilean capital of Santiago, Metal Bulletin understands.  The Brazilian steel institute, Aço Brasil, was “surprised” when the country’s finance ministry accepted that the adoption of anti-dumping tariffs against imports of hot-rolled coil (HRC) from China and Russia would be “detrimental” to the national industrial chain.  Spot prices for ammonium paratungstate (APT) climbed last week in Europe, buoyed by tightening availability of the material and strong downstream demand, as the market considered the effects of Xiamen Tungsten being temporarily denied its export license. Russian producers have significantly increased their prices for hot- and cold-rolled steel sheet from January production for domestic buyers, amid favorable export market sentiment.