Feasibility of using spectral techniques in potash mining and processing

钾肥生产在萨斯喀彻温省是一个巨大的、具有重要经济意义的行业。除氯化钾外，钾矿还含有大量的盐酸盐(氯化钠)。这两种矿物在化学和物理上的相似性使它们很难在矿石中相互区分。这就导致了向磨机保持一致的原料的问题。在测定溶液中氯化钾和氯化钠的相对浓度时也出现了类似的问题。目前的技术水平是使用自然产生的K40同位素的放射性衰变，或离线X射线技术。这些方法所需的设备昂贵，不利于在线监测和过程控制。 紫外-可见-近红外光谱和成像还没有被彻底地研究来区分这两种矿物。在固相中，纯氯化钾和氯化钠的可见光和近红外光谱几乎无法区分。然而，来自矿工的轶事证据表明，矿层中的矿物之间存在视觉差异。在溶液中，通过对水吸收带的副作用分析，建立了用光谱分析测定总氯离子浓度的方法。关于溶液中盐的形态的研究工作有限。 这项工作建议系统地研究光谱和成像技术是否可以在钾肥行业的两个场景中应用。将开发测量高温溶液吸收光谱的技术，并研究单组分和多组分溶液的光谱特性。将在使用机器视觉和成像光谱技术进行矿石分级方面进行探索性工作。这些研究将在光谱学领域创造新的知识，并支持开发工业上可行的在线评估工具。

Potash (KCl) production is a large and economically significant industry in Saskatchewan. Along with KCl, potash ore contains large quantities of Halite (NaCl). The chemical and physical similarity between these two minerals make them difficult to distinguish from each other in the ore. This leads to problems maintaining a consistent feedstock to the mill. A similar problem arises in determining the relative concentrations of KCl and NaCl in solution. The current state of the art is to use the radioactive decay of the naturally occurring K40 isotope, or off-line X-ray techniques. The equipment required for these approaches is expensive and not conducive for on-line monitoring and process control. UV-Visible-NIR spectroscopy and imaging have not been thoroughly investigated for distinguishing between these two minerals. In the solid phase, the visible and near-infrared spectra of pure KCl and NaCl are virtually indistinguishable. However, anecdotal evidence from miners suggests visual differences between minerals in the ore formation. In solution, it has been established that total Cl ion concentration may be determined using spectroscopy by analysis of side-effects on water absorption bands. Limited work has been done on speciation of the salts in solution. This work proposes to systematically study whether spectroscopic and imaging techniques can be applied in two scenarios in the potash industry. Techniques will be developed to measure absorption spectra of high-temperature solutions, and the spectral characteristics of single and multiple-species solutions investigated. Exploratory work will be conducted on using machine vision and imaging spectroscopy techniques for ore grading. These investigations will create new knowledge in the area of spectroscopy, and support the development of industrially viable on-line assessment tools.