Comminution circuits for compact itabirites

Abstract In the beneficiation of compact Itabirites, crushing and grinding account for major operational and capital costs. As such, the study and development of comminution circuits have a fundamental importance for feasibility and optimization of compact Itabirite beneficiation. This work makes a comparison between comminution circuits for compact Itabirites from the Iron Quadrangle. The circuits developed are: a crushing and ball mill circuit (CB), a SAG mill and ball mill circuit (SAB) and a single stage SAG mill circuit (SSSAG). For the SAB circuit, the use of pebble crushing is analyzed (SABC). An industrial circuit for 25 million tons of run of mine was developed for each route from tests on a pilot scale (grinding) and industrial scale. The energy consumption obtained for grinding in the pilot tests was compared with that reported by Donda and Bond. The SSSAG route had the lowest energy consumption, 11.8kWh/t and the SAB route had the highest energy consumption, 15.8kWh/t. The CB and SABC routes had a similar energy consumption of 14.4 kWh/t and 14.5 kWh/t respectively.

摘要 在致密铁英岩（Itabirite）的选矿工艺中，破碎与磨矿环节占据了主要的运营与资本成本。因此，粉碎回路（comminution circuits）的研究与开发，对致密铁英岩选矿项目的可行性论证与工艺优化具有基础性重要意义。本研究针对取自四角铁矿区（Iron Quadrangle）的致密铁英岩，对多种粉碎回路方案开展对比分析。所考察的回路包括：破碎-球磨回路（CB）、自磨机-球磨回路（SAB）以及单段自磨回路（SSSAG）。针对SAB回路，本研究还分析了砾石破碎工艺的应用效果（SABC）。基于中试（磨矿）与工业规模试验数据，本研究为每条工艺路线设计了处理能力达2500万吨原矿（run of mine）的工业生产回路。将中试磨矿环节测得的能耗数据，与Donda及邦德（Bond）所报道的结果进行了对比。结果表明：单段自磨回路（SSSAG）的能耗最低，为11.8千瓦时/吨；自磨机-球磨回路（SAB）的能耗最高，为15.8千瓦时/吨；破碎-球磨回路（CB）与砾石破碎型自磨机-球磨回路（SABC）的能耗相近，分别为14.4千瓦时/吨与14.5千瓦时/吨。