磁选-重选-浮选组合新工艺分选氟碳铈矿型稀土矿的试验研究

Experimental Study on a Novel Combined Beneficiation Technique for Bastnaesite Type RE Ore Using Magnetic-Gravity-Flotation Separation

采用矿物自动分析仪(MLA)查明了四川牦牛坪稀土矿的矿物组成、嵌布粒度特征,对比分析了主要矿物的密度、莫氏硬度、比磁化系数和磁性的工艺特性差异,利用湿式高梯度强磁选-重选-浮选的组合工艺进行了选矿试验研究。结果表明:主要稀土矿物氟碳铈矿粒度多在1.28~0.04 mm范围内,具有顺磁性,而重晶石、萤石、正长石和石英呈现非磁性,此磁性差异是强磁选能预先富集的关键矿物学因素。通过实验确定最佳工艺条件和结果为:在-1.0 mm粒径,1.0 T背景场强下湿式强磁选粗选,强磁选精矿分级成3个粒级物料,-1.0^+0.4 mm物料进行粗砂摇床重选,-0.4+0.074和-0.074 mm物料分别进行细砂摇床重选,各重选中矿合并,在0.6 T背景场强下湿式强磁选精选,磁选精矿与重选精矿合并,获得REO品位65.49%,回收率67.80%的磁重稀土精矿;磁选精选中矿与摇床尾矿合并成REO 2.10%的稀土中矿,在磨矿细度-0.043 mm占70%,pH 8~9,水玻璃用量714 g·t^(-1)原矿,捕收剂GSY 1033 g·t^(-1)原矿下进行常温浮选,获得REO品位67.84%,回收率15.46%的浮选稀土精矿;两种稀土精矿REO平均品位65.93%,总回收率83.26%。

Minerals composition and disseminated grain size features for a rare earth ore in Maoniuping deposit,Sichuan were detected by Mineral Liberation Analyser（ MLA） and beneficiation characteristicsdifferences of main minerals such as density,Moh＇s hardness,relative magnetic susceptibility and magnetism were analyzed,contrastively. Beneficiation tests were carried out by a novel combined technique ofwet high intensity magnetic-gravity-flotation separation. The results showed that bastnaesite was the primary rare earth bearing mineral with paramagnetic feature and particle size of 1. 28 - 0. 04 mm,but barite,fluorite,orthoclase and quartz were diamagnetic. The magnetic characteristic difference was a key mineralogical factor of pre-concentration by high intensity magnetic separation（ HIMS）. Optimal conditions and results were determined through the experimental study as follows,the concentrate from wet HIMS rougher（-1. 0 mm size and 1. 0 T background field） were classified into three different size products（-1. 0 ＋ 0. 4,-0. 4 ＋0. 074 and -0. 074 mm）,then the two formers were treated by coarse grain shaking tables and the latter was treated by fine grain shaking table,respectively,and all tables middlings were selected by wet HIMS（ 0. 6 T background field） together,magnetic-gravity separation RE concentrate assaying REO 65. 49% at 67. 80% recovery was obtained. The REO 2. 10% middlings formed by wet HIMS middlings and shaking tables tailings were treated by flotation at room temperature（-0. 043 mm grinding fineness 70%,pH 8 - 9,sodium silicate dosage 714 g·t（-1）,collector GSY dosage 1033 g·t（-1））,flotation RE with concentrate assaying REO 67. 84% with 15. 46% recovery was produced. The average REO 65. 93% at 83. 26% total recovery were obtained by the whole magnetic-gravity-flotation separation beneficiation technique.