By understanding minerals as crystals, a crystallization-controlled methodology was performed to enhance the floatability of soluble minerals. Here, aimed strategies were applied to modulate the crystallization of KCl salt to grow crystals with various shapes as cubic-, hopper- and needle-like structure. Stereoscope and scanning electronic microscopy (SEM) helped to unveil the morphologies where X ray diffraction (XRD) characterized their high crystallinities. Afterwards, Atomic Force Microscope (AFM) was performed to research the crystallizing behaviors that cubic-like structure was obtained by turbid fast growth, while hopper-like structure formation was due to the constant high supersaturation and needle-like crystal occurred under still fast crystallization. Flotation tests with octadecylamine hydrochloride (ODA) as collector demonstrated the floatability of samples obeyed the order as needle-like (96.19 %) > hopper-like (81.59 %) > cubic-like (80.08 %) KCl samples. The mechanism was studied by surface area and related interaction tests. BET result demonstrated the highest surface area of needle-like structure than that of hopper-like and cubic-like structure. Besides, induction time combined with adhesion & desorption force tests further explained the better interaction of needle-like sample with bubble than cubic-like sample. While the special structure of hopper-like structure with lower weight but inner filled solution resulted in its near equivalent floatability with cubic-like sample. In conclusion, a new strategy for promoting flotation behavior by designing the crystallization of soluble KCl was proposed, shedding some light on further application on other soluble or semi-soluble minerals.

中文翻译：

---

通过控制结晶改进钾盐浮选的新策略

通过将矿物质理解为晶体，采用结晶控制方法来增强可溶性矿物质的可浮性。在这里，采用有针对性的策略来调节 KCl 盐的结晶，以生长各种形状的晶体，如立方体、漏斗状和针状结构。立体镜和扫描电子显微镜 (SEM) 有助于揭示 X 射线衍射 (XRD) 表征其高结晶度的形态。随后，通过原子力显微镜（AFM）研究了结晶行为，通过浑浊的快速生长获得了立方体结构，而漏斗状结构的形成是由于持续的高过饱和度，并且在仍然快速结晶的情况下出现了针状晶体。以盐酸十八胺(ODA)为捕收剂的浮选试验表明，样品的可浮性顺序为：针状(96.19%)>漏斗状(81.59%)>立方状(80.08%)KCl样品。通过表面积和相关相互作用测试研究了该机理。 BET结果表明针状结构比漏斗状和立方体结构具有最高的表面积。此外，诱导时间结合粘附力和解吸力测试进一步解释了针状样品与气泡的相互作用优于立方体样品。而漏斗状结构的特殊结构，重量较轻，内部充满溶液，使其可浮性与立方体样品接近。总之，提出了一种通过设计可溶性 KCl 结晶来促进浮选行为的新策略，为其他可溶性或半可溶性矿物的进一步应用提供了一些启示。