Novel strategies for CO2 utilization and storage in mineral processing

矿物碳储存(MCS)是一种碳固存，二氧化碳与碱性矿物反应生成固体碳酸盐。虽然MCS与其他碳储存技术相比具有优势，但它需要大量的矿物原料。通过采矿获得这种矿物原料可能会对环境造成很大的影响。选矿废物是MCS原料的替代来源，这些原料已经开采和研磨得很细。在这个项目中，我们建议开发一种综合工艺，同时储存二氧化碳，提高选矿作业的效率，增强尾矿稳定性，消除废物。具体地说，我们计划研究(1)活性矿物碳化对超镁铁镍矿石浮选的影响，(2)探索使用二氧化碳作为浮选气体来沉淀镁离子和钙离子，并在同时储存碳的同时改善工艺水的条件，(3)研究利用矿物碳化产生超镁镍尾矿中的胶凝材料，以通过干法堆积来加强尾矿管理，以及(4)研究矿物碳化作用将超镁铁尾矿转化为有价值的商品并消除废物产生的可能性。如果成功，将开发新技术，不仅提高采矿和选矿作业的可持续性，还将通过储存碳和销售新产品产生新的收入来源，并可能使以前不经济的采矿作业变得可行。这些结果对迫切需要开发新技术来处理低品位矿石和管理尾矿的加拿大矿业公司以及从矿业部门就业中受益的加拿大人来说都很重要。其他好处包括缓解气候变化，减少采矿和矿物加工对土地和水的影响。

Mineral carbon storage (MCS) is a type of carbon sequestration where carbon dioxide is reacted with alkaline minerals to form solid carbonates. Although MCS has advantages compared to other carbon storage techniques, it requires large quantities of mineral feedstock. The acquisition of this mineral feedstock through mining can have a large environmental footprint. Mineral processing wastes are an alternative source of MCS feedstock which are already mined and finely ground. In this project, we propose to develop an integrated process to simultaneously store carbon dioxide, improve the efficiency of mineral processing operations, enhance tailings stability and eliminate waste. Specifically, we plan to investigate (1) the impact of active mineral carbonation on the flotation of ultramafic nickel ores, (2) explore the use of CO2 as a flotation gas to precipitate magnesium and calcium ions and condition process water while simultaneously storing carbon, (3) study the use of mineral carbonation to generate cementitious materials in ultramafic nickel tailings to enhance tailings management by dry-stack, and (4) examine the potential for mineral carbonation to transform ultramafic tailings into valuable commodities and eliminate the production of waste materials. If successful, new technologies will be developed that not only increase the sustainability of mining and mineral processing operations, but also generate new streams of revenue through the storage of carbon and sale of new products, and could make previously uneconomic mining operations feasible. These outcomes are important for Canadian mining companies, who urgently need to develop new technologies to process low-grade ores and manage tailings, as well as for Canadians in general who benefit from employment in the mining sector. Additional benefits include climate change mitigation and reduced impacts of mining and mineral processing on lands and water.