ABSTRACT

Information obtained from comminution test work at the laboratory scale can be utilized to characterize ore types and predict their behavior during comminution at the industrial scale. Comminution tests with a laboratory-scale rod and ball mill of 13 predefined ore types from the Per Geijer iron oxide-apatite deposits were conducted. The grinding setup refers to the so-called Malmberget method used at LKAB, characterized by a subsequent circuit of rod and ball mill grinding. The highest P₈₀ values were obtained by grinding only in the rod mill for 10 min (step A). Ball mill grinding for 25 min (step B) and 35 min (step C) gave a very narrow range of P₈₀ values. Hematite-dominated ore types had significantly higher P₈₀ values after the primary grinding step A compared to the other ore types. Generally, Fe content increased in finer particle size classes while CaO and P contents decreased. The influence of silicates or phosphates is dependent on the dominant iron oxide. Magnetite-dominated ore types are more likely to be affected in their comminution behavior by the presence of silicate minerals. In contrast, hematite-dominant ore types are instead influenced by the presence of apatite. The difference in the degree of liberation of magnetite and hematite between ore types depends on size fractions rather than the amount of gangue in the ore most likely caused by very fine intergrowth of both iron oxides. A consolidation from 13 to 8 ore types is favored, supporting possible future mining of the Per Geijer deposits.

摘要

从实验室规模的粉碎测试工作中获得的信息可用于表征矿石类型并预测它们在工业规模粉碎过程中的行为。使用实验室规模的棒磨机和球磨机对 Per Geijer 氧化铁磷灰石矿床的 13 种预定义矿石类型进行了粉碎测试。研磨装置是指 LKAB 使用的所谓 Malmberget 方法，其特点是随后的棒磨机和球磨机研磨循环。通过仅在棒磨机中研磨 10 分钟（步骤 A）获得最高 P _80值。球磨机研磨 25 分钟（步骤 B）和 35 分钟（步骤 C）给出了非常窄的 P ₈₀值范围。以赤铁矿为主的矿石类型具有显着较高的 P ₈₀与其他矿石类型相比，初级研磨步骤 A 后的值。一般来说，Fe含量在更细粒度等级中增加，而CaO和P含量减少。硅酸盐或磷酸盐的影响取决于主要的氧化铁。以磁铁矿为主的矿石类型更容易受到硅酸盐矿物的存在的影响。相反，以赤铁矿为主的矿石类型反而受到磷灰石存在的影响。矿石类型之间磁铁矿和赤铁矿释放程度的差异取决于尺寸分数，而不是矿石中脉石的数量，这很可能是由两种氧化铁的非常精细的共生引起的。有利于将 13 种至 8 种矿石类型进行合并，从而支持未来可能开采 Per Geijer 矿床。