高钙镁钛精矿氧化改性–物理冶金分选协同提钛研究

Study on Synergistic Titanium Extraction from High-Calcium-Magnesium Titanium Concentrate via Oxidative Modification and Physical Metallurgical Separation

摘要: 本文针对高钙镁钛精矿中钙、镁等杂质元素赋存状态复杂、难以高效分离的问题，系统研究了氧化改性技术对其含钛物相赋存状态的影响规律，并探究了物理冶金分选工艺的优化路径。通过设计三因素三水平正交实验(温度800℃~1200℃、时间30~90 min、氧气流量3~5 L/min)，结合XRD表征手段，阐明了氧化改性过程中物相演变机制。结果表明，1200℃下保温90 min、氧气流量4 L/min时，钛精矿中TiO₂品位为43.99%，钙、镁杂质稀释率分别为32.32%和37.69%，为后续分选奠定物相基础。进一步分析了磁选、浮选及联合工艺的分选效果。研究发现，单独磁选可使TiO₂品位从43.99%提升至45.77%，但受限于弱磁性杂质的选择性；以辛酰羟肟酸为捕收剂单独浮选时，精矿TiO₂品位为46.39%，回收率为67.74%。磁选–浮选联合分选时：磁选优先脱除Fe氧化物(精矿TiO₂品位为45.77%)，尾矿经浮选去除Ca、Mg、Al、Si等杂质后，TiO₂品位进一步提升至48.95%，较原矿提升4.96%，其回收率达到57.23%。分析表明，氧化改性通过重构金红石相与非含钛物相的物理性质差异，显著增强了分选效率，联合工艺的协同效应使杂质脱除率和钛富集效果最优。

Abstract: Aiming at the problem that impurity elements such as calcium and magnesium in high-calcium-magnesium titanium concentrate have complex occurrence states and are difficult to separate efficiently, this paper systematically studies the influence law of oxidative modification technology on the occurrence state of titanium-bearing phases, and explores the optimization path of physical metallurgical separation processes. By designing a three-factor and three-level orthogonal experiment (temperature: 800˚C~1200˚C, time: 30~90 min, oxygen flow rate: 3~5 L/min) combined with XRD characterization, the phase evolution mechanism during the oxidative modification process is clarified. The results show that when the temperature is 1200˚C, the holding time is 90 min, and the oxygen flow rate is 4 L/min, the TiO₂ grade in the titanium concentrate reaches 43.99%, and the dilution rates of calcium and magnesium impurities are 32.32% and 37.69% respectively, laying a phase foundation for subsequent separation. The separation effects of magnetic separation, flotation and combined processes are further analyzed. The study finds that single magnetic separation can increase the TiO₂ grade from 43.99% to 45.77%, but it is limited by the selectivity of weakly magnetic impurities. For single flotation with optimized caprylhydroxamic acid collector, the TiO₂ grade of the concentrate is 46.39% and the recovery rate is 67.74%. For the magnetic-flotation combined separation: magnetic separation first removes Fe oxides (the TiO₂ grade of the concentrate is 45.77%), and after the tailings are subjected to flotation to remove impurities such as Ca, Mg, Al and Si, the TiO₂ grade is further increased to 48.95%, which is 4.96 percentage points higher than that of the raw ore, with a recovery rate of 57.23%. Analysis shows that oxidative modification significantly enhances separation efficiency by reconstructing the difference in physical properties between rutile phase and non-titanium-bearing phases, and the synergistic effect of the combined process achieves the optimal impurity removal rate and titanium enrichment effect.