Numerical investigation of the liberation of critical raw materials in the form of Engineered Artificial Minerals (EnAMs) from tailored solidified slag phases by DEM-based comminution

在矿物、金属和天然材料中，经济上最重要、供应风险高的原材料被称为关键原材料。关键的原材料对于各种工业部门的运作和完整是必不可少的，这一方面要求它们有多样化和不受扭曲的进入全球市场的机会。另一方面，可以通过减少、再利用和再循环关键原材料，以及为它们寻找新的来源来增加可用性。关键原料可能的新来源，但大多尚未开发，是来自火法冶金过程的固化渣系统。在这些系统中，它通常针对主金属相。所有其他材料都被驱入渣相，成为大量有价元素的载体。当炉渣凝固时，它可以产生晶体，这可以看作是人工矿物，称为工程人工矿物（EnAMs），其中有价值的元素被富集。为了进一步处理enam，它们需要通过粉碎来释放，并且通常作为颗粒分离。所提出的研究工作的总体目标是利用离散元方法（DEM）建模来预测从渣系统中释放EnAM。这就需要在尺寸减小和解放的意义上对粉碎进行建模。为了在DEM中包含后者的运行效率，采用了粒子替换法（PRM）。由于尚不完全清楚随机或非随机破碎是否是控制含矿渣EnAM粉碎的主要破碎模式，因此SPP 2315的第一个资助期追求的假设是，它主要由随机破碎控制。因此，从某种意义上理解随机破损是不依赖于纹理的-然而，对成分的依赖是实现的。作为第二个资助期的一部分，如果这证明是相关的，则扩展DEM建模框架以包括非随机纹理相关的破损。在SPP 2315的第一个资助期内，将开发一个建模框架，该框架将涵盖从静态到动态的各种加载条件。根据SPP 2315的考虑，该框架将被校准到至少一个含矿渣的EnAM体系。通过将其应用于实验室规模的粉碎设备，并对获得的尺寸分布和解离度的实验数据进行基准测试，将确保DEM可以应用于含有EnAMs的复杂渣系统。这允许利用DEM的预测能力来分析粉碎过程的最佳互连，以便从炉渣中释放EnAM作为第二步。

Among minerals, metals and natural materials those raw materials that are most important economically and have a high supply risk are called critical raw materials. Critical raw materials are essential to the functioning and integrity of a wide range of industrial branches, which requires on the one hand a diversified and undistorted access to global markets for them. On the other hand, increased availability can be achieved by reducing, reusing and recycling the critical raw materials, but also by finding new sources for them.Possible new sources for critical raw materials, yet mostly not exploited, are solidified slag systems from pyrometallurgical processes. In these systems it is usually aimed for the main metal phase. All other materials are driven into the slag phase, which becomes a carrier of a broad number of valuable elements. When the slag solidifies it can generate crystals, which can be seen as artificial minerals referred to as Engineered Artificial Minerals (EnAMs) in which the valuable elements are enriched. In order to further process the EnAMs, they need to be liberated by comminution and are often separated as particles. Overall aim of the proposed research work is to contribute to the prediction of EnAM liberation from slag systems by utilizing Discrete Element Method (DEM) modelling. This requires to model both comminution in the sense of size reduction accompanied by liberation. To include the latter run-time efficient in the DEM, the particle replacement method (PRM) is used. As it is yet not fully clear if random or non-random breakage is the dominant breakage mode to govern comminution of EnAM containing slags, the hypothesis that it is governed mostly by random breakage is pursued as part of the first funding period of SPP 2315. Random breakage is thereby understood in the sense that breakage is not texture dependent – the dependence on composition is however realized for. As part of the second funding period, the DEM modelling framework is extended to include also non-random texture dependent breakage, if this proofs to be relevant.Throughout the first funding period of SPP 2315 a modeling framework will be developed that will cover various loading conditions from static to dynamic. The framework will be calibrated to at least one EnAM containing slag system as considered throughout SPP 2315. By applying it to laboratory-scale comminution apparatuses and a benchmarking against experimental data on obtained size distributions and liberation degrees, it will be ensured that the DEM can be applied to complex slag systems containing EnAMs. This allows to utilize the predictive capabilities of the DEM to analyze on optimal interconnections of comminution processes for EnAM liberation from slags as a second step.