The paper considers the results of the application of dry magnetic separation on samples of ferruginous quartzites of the Kostomuksha ore field, represented by refractory ore, free-milling ore, and their mixture. The assessment of the influence of the ore texture on the technological parameters of dry magnetic separation indicates their insignificant changes: the yield of the non-magnetic product varies from 12.4 to 13.5%, and the Fe_total content in the magnetic product increases by 1.11–1.14 times. A decrease of at least 15% in the number of harmful impurities was found: S by 16.2–17.3%, SiO₂ by 15.5–21.1%, and Al₂O₃ by 39.1–48.4%. The authors have performed a comparative assessment of the granularity of the initial ore and the magnetic product with the measurement of energy consumption, as well as an analysis of the magnetite liberation on particle sizes of less than 2 mm. It was found that due to the release of a non-magnetic product in the amount of 12.3–14.5%, represented by non-magnetite or weakly mineralized rock varieties, energy consumption for the crushing process is reduced by at least 5%. The mineral liberation assessment showed that mainly free magnetite is contained in the −0.4 mm fineness class. It was found that in the magnetic separation product of the refractory ore sample, the amount of liberated magnetite in the size class −1 + 0 mm increases by 12.1% compared to the initial ore sample. For the free-milling ore sample, the opposite trend is observed: a decrease in the amount of free magnetite by 30.9% in the magnetic product. Analysis of the magnetite liberation in the mixture indicates deterioration in the results obtained during the separate crushing of refractory and free-milling ore and a decrease in the amount of liberated magnetite in the magnetic product by 60% compared to the initial ore.

中文翻译：

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干式磁选对铁质石英石解体过程的影响分析

本文考虑了干式磁选对 Kostomuksha 矿田铁质石英岩样品的应用结果，这些样品以难选矿石、自由磨矿矿石及其混合物为代表。对矿石质地对干式磁选工艺参数影响的评估表明其变化不显着：非磁性产品的产率从12.4%到13.5%不等，磁性产品中Fe_总含量增加1.11- 1.14 倍。发现有害杂质的数量至少减少了 15%：S 减少了 16.2-17.3%，SiO ₂减少了 15.5-21.1%，Al ₂ O ₃39.1–48.4%。作者通过能耗测量对初始矿石和磁性产品的粒度进行了比较评估，并对粒度小于 2 毫米的磁铁矿释放进行了分析。结果表明，由于释放了12.3-14.5%的非磁性产物，以非磁铁矿或弱矿化岩石品种为代表，破碎过程的能耗至少降低了5%。矿物释放评估表明，-0.4 毫米细度等级中主要包含游离磁铁矿。发现在难选矿石样品的磁选产物中，粒度等级-1+0mm的游离磁铁矿的量比初始矿石样品增加了12.1%。对于自由磨矿样品，观察到相反的趋势：磁性产品中游离磁铁矿的量减少了 30.9%。对混合物中磁铁矿释放的分析表明，在分别破碎耐火矿石和自由磨矿矿石期间获得的结果变差，并且与初始矿石相比，磁性产品中释放的磁铁矿量减少了 60%。