菱镁矿煅烧浮选除钙及其机理

Separability of calcium from calcining magnesite by flotation and its mechanism

对浮选脱硅后在850℃下煅烧3 h的菱镁矿精矿进行浮选试验,分别以油酸钠和十二胺为捕收剂,水玻璃和六偏磷酸钠为调整剂研究了含钙杂质的可选性。通过ζ电位测定分析了浮选机理。结果表明:以十二胺和水玻璃为捕收剂和活化剂进行的反浮选,可以得到MgO品位和回收率分别为76.48%和79.75%,CaO含量为0.24%的MgO与Mg(OH)2混合物精矿。煅烧后的白云石表面因包裹了氢氧化钙薄膜而吸附了水玻璃水解产物H2SiO3和SiO32聚合成的胶粒被活化,活化的煅烧白云石再次吸附十二胺,表面变得疏水而上浮。运用Material Studio软件模拟了十二胺对经活化后的煅烧白云石的吸附,比较了六偏磷酸钠与水玻璃两种调整剂的优劣。

The rough magnesite concentrate, which has been reduced silica with flotation, was separated with a flotation flowsheet again after being calcined at 850 ℃ for 3 h. The separability of dolomite from magnesite was studied, and modifier and collector were sodium silicate, sodium hexametaphosphate and sodium oleate, laurylamine. The flotation mechanism was analyzed through the zeta potential. The results show that MgO and Mg（OH）2 mixed concentrates with MgO grade, recovery and CaO content of 76.48%, 79.75% and 0.24%, respectively, are obtained in the reverse flotation tests using laurylamine and sodium silicate as collector and activator. The dolomite wrapped by calcium hydroxide adsorbed colloidal particle consists of H2SiO3 and SiO32-, H2SiO3 and SiO32- are the product of sodium silicate. Subsequently, the surface of dolomite becomes hydrophobic after adsorbing laurylamine. And using the software Material Studio to simulate the adsorption, when sodium hexametaphosphate and sodium silicate are used as adjustment agent.