聚天冬氨酸对菱镁矿与白云石可浮性的影响

Effect of Polyaspartic Acid on the Floatability of Magnesite and Dolomite

以油酸钠为捕收剂,在碱性条件下考察调整剂聚天冬氨酸(PASP)对菱镁矿与白云石可浮性的影响;通过接触角测量、红外光谱、XPS分析以及吸附量测试分析了聚天冬氨酸在两种矿物表面的作用机理。单矿物可浮性试验表明,油酸钠用量为160 mg/L、pH=11的条件下,PASP用量3 mg/L可以使菱镁矿与白云石之间获得80.78百分点的显著单矿物浮选差;在人工混合矿浮选试验中,发现PASP可以选择性抑制白云石实现菱镁矿与白云石的分离。接触角测量结果表明,PASP显著降低了白云石的接触角,增强了白云石的亲水性。红外光谱分析发现,PASP在白云石表面发生化学吸附,阻碍了油酸钠对白云石的捕收,但由于PASP在菱镁矿表面的吸附很弱,对菱镁矿的可浮性基本没有影响。XPS分析表明,PASP更容易吸附在白云石表面的Ca位点。吸附量测试结果显示,PASP能显著降低油酸钠在白云石表面的吸附量,而对油酸钠在菱镁矿表面的吸附影响较小。因此,聚天冬氨酸是一种对白云石选择性作用较强的调整剂,可以实现菱镁矿与白云石的浮选分离。

Using sodium oleate as collector,the effect of polyaspartic acid(PASP)on the floatability of magnesite and dolomite was investigated under alkaline conditions;The action mechanism of polyaspartic acid on the surface of the two minerals was analyzed by contact angle measurements,infrared spectrum analysis,X-ray photoelectron spectroscopy(XPS)analysis and adsorption measurements.Single mineral floatability tests found that under the condition of sodium oleate dosage of 160 mg/L and pulp pH of 11,the dosage of 3 mg/L PASP can make a significant single mineral flotation difference of 80.78%between magnesite and dolomite;In the artificial mixed ore flotation test,it was found that PASP could selectively inhibit dolomite to achieve the separation of magnesite and dolomite.The contact angle measurement shows that PASP significantly reduces the contact angle of dolomite and enhances the hydrophilicity of dolomite,but has no effect on the floatability of magnesite.Infrared spectrum analysis found that the chemical adsorption of PASP on the surface of dolomite hindered the collection of sodium oleate on dolomite,but basically did not affect the floatability of magnesite.XPS analysis shows that PASP is more easily adsorbed at the Ca site on the surface of dolomite.The adsorption measurement results show that PASP can significantly reduce the adsorption capacity of sodium oleate on the surface of dolomite,but has little effect on the adsorption capacity of sodium oleate on the surface of magnesite.It can be seen that polyaspartic acid is a regulator with strong selectivity for dolomite,which can seperate magnesite from dolomite by flotation.