油酸钠与十二胺混合药剂浮选胶磷矿试验研究

Experimental Study on Flotation of Collophane Using a Mixed Reagent of Sodium Oleate and Dodecylamine

摘要: 本文以湖北某胶磷矿为研究对象，对矿石进行了矿物成分分析，确认其主要脉石矿物为石英，并含有少量Al₂O₃、Fe₂O₃、MgO等杂质。矿石中SiO₂与MgO含量分别为17.53%和1.8%，属于典型的中低品位硅钙质胶磷矿。针对该矿石特性，研究了反浮选分步加药工艺以实现脱镁脱硅。实验发现，分步加药可获得P₂O₅品位30.7%、回收率73.81%的磷精矿，但尾矿品位仍偏高。为此，进一步探索了油酸钠与十二胺混合加药的反浮选流程：在磨矿细度−0.074 mm占82.3%的条件下，以硫酸12 kg/t、Ca²⁺ 500 g/t、油酸钠3 kg/t、十二胺200 g/t、MIBC 570g/t为粗选药剂制度；粗精矿经十二胺100 g/t一次精选脱硅，粗选尾矿与精选尾矿合并后以Ca²⁺ 200 g/t、MIBC 380 g/t进行扫选。结果表明，该混合加药工艺能够达到常规双反分步浮选的效果，在开路浮选条件下获得P₂O₅品位30.69%、回收率70.37%、MgO含量仅为0.61%的磷精矿，实现了对该中低品位混合型磷矿的有效分选，为同类矿石的浮选分离提供了可行参考。

Abstract: This study investigates the beneficiation of phosphate ore from Hubei Province, China. Mineralogical analysis revealed that quartz is the dominant gangue mineral, accompanied by minor amounts of Al₂O₃, Fe₂O₃, and MgO. The chemical composition, characterized by SiO₂ and MgO contents of 17.53% and 1.8%, respectively, categorizes this ore as a typical mid-to low-grade siliceous-calcareous phosphate rock. Based on its mineralogical characteristics, a reverse flotation process employing staged reagent addition was investigated for the removal of magnesium and silica. A phosphate concentrate assaying 30.7% P₂O₅ with a recovery of 73.81% was achieved; however, the tailings grade remained undesirably high. Consequently, a reverse flotation process utilizing a combined reagent scheme of sodium oleate and dodecylamine was adopted. At a grinding fineness of 82.3% passing 0.074 mm, the rougher flotation conditions were as follows: sulfuric acid at 12 kg/t, Ca²⁺ at 500 g/t, sodium oleate at 3 kg/t, dodecylamine at 200 g/t, and MIBC (methyl isobutyl carbinol) at 570g/t. The rougher concentrate was subjected to one cleaning step for silica removal using dodecylamine at 100 g/t. The combined rougher and cleaner tailings were subjected to a scavenging step with Ca²⁺ at 200 g/t and MIBC at 380g/t. The results demonstrate that the reverse flotation utilizing the combined sodium oleate and dodecylamine scheme achieved a separation performance comparable to that of the conventional double reverse flotation process with staged reagent addition. Under open-circuit conditions, a final concentrate with a P₂O₅ grade of 30.69%, a recovery of 70.37%, and an MgO content of only 0.61% was obtained. This process enables the efficient beneficiation of this mid- to low-grade mixed-type phosphate ore and provides a valuable reference for processing similar ores.