ABSTRACT

The surface chemistry of cassiterite mineral and selective dispersion-flocculation-flotation studies on cassiterite tailings have been investigated using xanthan gum. Mineralogical studies indicate that quartz is the major mineral encapsulating cassiterite. The results of the adsorption, electrokinetic, co-precipitation, and Fourier Transform Infrared spectroscopic studies indicate that xanthan gum adsorbs on cassiterite by both physical and chemical forces. The adsorption density of xanthan gum for cassiterite decreases with an increase in pH, whereas it does not adsorb on quartz in the pH range of 3 to 12. The Gibbs free energy of adsorption for cassiterite is determined to be −35.7 kJ/mole, indicative of chemisorption. The zeta potential of cassiterite becomes more negative and its isoelectric point is shifted to more acidic pH values, attesting to specific adsorption of xanthan gum, whereas that of quartz remains unaltered, after its addition. The Fourier Transform Infrared spectroscopic investigations reveal that the adsorption of xanthan gum on cassiterite is governed by both hydrogen bonding and chemical interaction. The complexation of xanthan gum with Sn ions in the bulk solution is confirmed by dissolution and co-precipitation studies. Selective dispersion-flocculation-flotation tests on gravity tailings from Gasambya mines, Rutongo, Rwanda, demonstrate that a cleaner concentrate of 64.8% grade of Sn with 89% recovery, containing 1.9% grade of SiO₂ with 1.3% recovery could be obtained, with a selectivity index of 27.4.

摘要

使用黄原胶研究了锡石矿物的表面化学和锡石尾矿的选择性分散-絮凝-浮选研究。矿物学研究表明，石英是包裹锡石的主要矿物。吸附、电动、共沉淀和傅里叶变换红外光谱研究的结果表明，黄原胶通过物理和化学力吸附在锡石上。黄原胶对锡石的吸附密度随着 pH 值的增加而降低，而在 3 到 12 的 pH 范围内它不会吸附在石英上。锡石的吉布斯吸附自由能被确定为 -35.7 kJ/mole，表明的化学吸附。锡石的 zeta 电位变得更负，其等电点向更酸性的 pH 值移动，证明黄原胶的特异性吸附，而石英在添加后保持不变。傅里叶变换红外光谱研究表明，黄原胶在锡石上的吸附受氢键和化学相互作用的控制。通过溶解和共沉淀研究证实了黄原胶在本体溶液中与 Sn 离子的络合。对来自卢旺达 Rutongo 的 Gasambya 矿山的重力尾矿进行选择性分散-絮凝-浮选试验表明，更清洁的 Sn 精矿具有 64.8% 的回收率和 89% 的回收率，含有 1.9% 的 SiO 傅里叶变换红外光谱研究表明，黄原胶在锡石上的吸附受氢键和化学相互作用的控制。通过溶解和共沉淀研究证实了黄原胶在本体溶液中与 Sn 离子的络合。对来自卢旺达 Rutongo 的 Gasambya 矿山的重力尾矿进行选择性分散-絮凝-浮选试验表明，更清洁的 Sn 精矿具有 64.8% 的回收率和 89% 的回收率，含有 1.9% 的 SiO 傅里叶变换红外光谱研究表明，黄原胶在锡石上的吸附受氢键和化学相互作用的控制。通过溶解和共沉淀研究证实了黄原胶在本体溶液中与 Sn 离子的络合。对来自卢旺达 Rutongo 的 Gasambya 矿山的重力尾矿进行选择性分散-絮凝-浮选试验表明，更清洁的 Sn 精矿具有 64.8% 的回收率和 89% 的回收率，含有 1.9% 的 SiO可以得到_{2 ，回收率为 1.3%，选择性指数为 27.4。}