改性水玻璃在萤石矿浮选中的应用及抑制机理

Application of NSO_H in Fluorite Ore Flotation and Its Depressing Mechanism

在对某碳酸盐型高泥萤石矿的选矿试验中,采用了新型抑制剂和新的流程:在常规条件下通过一次粗选脱除大部分矿泥和部分方解石,然后再进行方解石和萤石的浮选分离,经过一段磨矿—两粗—五精—两扫的选别流程获得了合格的精矿;其中精矿中CaF2品位95.37%,CaCO3品位3.06%,CaF2回收率76.61%,最终尾矿CaF2品位12.36%.研究表明,改性水玻璃NSOH中对方解石起主要抑制作用的为胶态硅酸和SiO2(OH)22-离子,并得出各组分对矿物抑制能力的顺序:SiO2(OH)22->Si(OH)4>HSiO3-.其抑制作用主要是由于不同矿物对胶态硅酸和SiO2(OH)22-离子的吸附能力不同,其中吸附能力强的矿物容易被水玻璃抑制,而那些吸附不牢固或基本不吸附硅酸和SiO2(OH)22-离子的矿物就不容易被抑制或基本不被抑制.

A new type depressant was introduced in the flotation test of a certain fluorite ore containing carbonates and lots of sludge. Part of calcite and most of fluorite were separated from sludge by bulk flotation under conventional conditions through a rougher as first step, then the fluorite and calcite were separated by another rougher. A process of several steps in cleaning flotation was needed to obtain desirable fluorite concentrates, including the grinding once, roughing twice, clean-out five times and scavenging twice successively. The contents of CaF2 and CaCO3 in concentrate are 95.37% and 3.06%, respectively, with a recovery rate of CaF2 76.61% and the grade of CaF2 in tailing 12.36%. Theoretical study showed that Si（OH）4 and SiO2（OH）2^2- are the main components to depress calcite mineral in modified sodium silicate and the sequence of depressibility is SiO2 （OH） 2^2- 〉 Si（OH）4 〉HSiO3^-. The depressibility was mainly due to the different adsorbabilities of Si （OH）4 and SiO2 （OH）2^2- for different minerals among which the highly adsorbable ones are easy to be depressed, while those minerals which cannot adsorb Si（OH）4 and SiO2 （OH）2^2- firmly even are unable to adsorb them are not easily to be depressed or cannot be depressed at all.