典型阴阳离子与晶质结构性差异菱镁矿在浮选体系下的相互作用

Interaction between typical anions/cations and structural differences in crystal structure of magnesite in flotation systems

自然界中的菱镁矿主要以显晶质和隐晶质两种结构存在,晶质结构的差异导致矿物在浮选过程中表现出不同的表面性质,如溶解度和亲疏水性等。在浮选过程中,常用的阴阳离子调整剂会促使两种晶质结构菱镁矿与捕收剂之间产生不同的相互作用,然而对于两种晶质结构的具体影响机理尚不明确。本文以显晶质和隐晶质结构差异作为区分,在十二胺阳离子捕收剂和油酸钠阴离子捕收剂作用下,研究了Fe^(3+)、Ca^(2+)、SiO_(3)^(2-)和CO_(3)^(2-)等阴阳离子对于两种晶质菱镁矿的可浮性影响。结果表明:在十二胺体系中,Fe^(3+)对矿物具有明显的抑制作用,显晶质和隐晶质菱镁矿的回收率分别降低70%和10%,Ca^(2+)、SiO_(3)^(2-)和CO_(3)^(2-)则产生了一定的活化作用,其中CO_(3)^(2-)的作用最强,两种晶质菱镁矿的回收率分别提高70%和40%。在油酸钠体系中,Fe^(3+)、Ca^(2+)对矿物的浮选具有抑制作用,Fe^(3+)作用时,两种矿物的回收率分别下降55%和20%;而SiO_(3)^(2-)和CO_(3)^(2-)对矿物的浮选则产生了活化作用,在CO_(3)^(2-)作用下显晶质和隐晶质菱镁矿的回收率分别提高10%和25%。在两种晶质结构菱镁矿的浮选体系中,CO_(3)^(2-)的加入会促进捕收剂在矿物表面的吸附,从而提高矿物的回收率,Fe^(3+)的加入则会在矿浆中形成亲水性的羟基铁配合物质,并罩盖于颗粒表面,降低矿物可浮性。隐晶质菱镁矿在矿浆中的溶解也会提高矿浆黏度,因此相较于显晶质菱镁矿,其受到的抑制作用相对较弱。在阴阳离子作用下,菱镁矿的浮选特性与其不同的晶质结构有着非常重要的联系。

Magnesite in nature mainly exists in two structures,crystalline and cryptocrystalline.The difference in crystal structure causes minerals to exhibit different surface properties,such as solubility and hydrophobicity,during the flotation process.In the flotation process,the commonly used anion and cation regulators will promote different interactions between the two crystalline structures magnesite and the collector,but the specific influence mechanism on the two crystal structures is not clear.In this paper,the effects of anions and cations,such as Fe^(3+),Ca^(2+),SiO_(3)^(2-)and CO_(3)^(2-),on the floatability of two crystalline magnesites were studied under the action of dodecamine cation collector and sodium oleate anion collector.The results show that Fe^(3+)has obvious inhibitory effect on minerals in dodecamine system,the recovery rates of crystalline magnesite and cryptocrystalline magnesite decrease by 70%and 10%,respectively.Ca^(2+),SiO_(3)^(2-)and CO_(3)^(2-)have certainly activating effects,among which CO_(3)^(2-)has the strongest effect,and the recovery rates of two crystalline magnesites increases by 70%and40%,respectively.In the sodium oleate system,Fe^(3+)and Ca^(2+)have inhibitory effects on the flotation of minerals,the recovery rates of the two minerals decreases by 55%and 20%,respectively,when Fe^(3+)is reacted.Ca^(2+)and Mg^(2+)have the activating effect on the surface of minerals,and the recovery rates of crystalline and cryptocrystalline magnesite increase by 10%and 25%,respectively.The different crystalline structures of magnesite affect its flotation characteristics under ionic conditions.The addition of CO_(3)^(2-)will promote the adsorption of sodium oleate on the surface of the mineral,thereby improve the recovery rates of the minerals.The addition of Fe^(3+)will promote the dissolution of magnesite and form a hydration layer on the surface of the particles,hinder the adsorption of collectors on the surface of the particles,thereby reduce the recovery rates of minerals.