Evolution and Innovation of Mineral Processing in China - MININGTEC.
A red copper plate, discovered in the ruins of Dachengshan in Hebei province, was recognized as a forged one rather than a cast one, which means it was probably made from natural copper during the Longshan Culture period (2200~2208 BC) in the Chinese history. The copperware, found in the Niangniang Tai relics in Wuwei city, Gansu province, contains 99.6% copper and 0.4% Sn, Pb, Sb and Ni, which was guessed to be made during the Qijia Culture about 2000~1900 BC in the Chinese history in the late Neolithic before Shang dynasty. This shows that Chinese ancestors were able to distinguish, sort and use some native metals and minerals more than 4000 years ago.
Magnetization in slurry (MIS) of weakly magnetic minerals by iron ions was investigated. The magnetic seeds (strongly magnetic particles) were synthesized by ferruginous chlorides directly in slurry instead of previous preparation... Magnetization in slurry (MIS) of weakly magnetic minerals by iron ions was investigated. The magnetic seeds (strongly magnetic particles) were synthesized by ferruginous chlorides directly in slurry instead of previous preparations of magnetic seeds by finely grinding mineral magnetite or specially synthesizing them separately in an aqueous solution. In this way, the growth of the seeds and their adsorption on the minerals simultaneously take place in the same slurry. That after MIS the recovery of weakly magnetic mineral limonite in a magnetic separator increased means the formation and adsorption of magnetic seeds on the surface of iron mineral limonite. The magnetization effect was evaluated by limonite recovery at a magnetic strength of 3.500 Gs in a magnetic separator. Mineral limonite was properly magnetized in the following slurry condition: molar ratio of Fe3+ to Fe2+ 1:3, slurry temperature of 45 °C and pH 10.5. The selectivity of the magnetization between minerals limonite and quartz was improved by adding surfactant sodium oleate. Keywords: Magnetization; Limonite; Iron salts; Sodium oleate; Magnetic separation