Mineral-water interactions in CO2 sequestration and mining environments

碳管理和封存是地球科学研究中的新兴领域，其动机是对气候变化影响的担忧以及碳定价日益增加的财务激励措施。在需要减少温室气体（GHG）排放的同时，由于对资源的需求增加，诸如尾矿（细粒废石）的矿山废物的产生正在升级。因此，采矿业必须制定更安全和更具成本效益的尾矿管理做法，同时改善环境绩效。拟议研究的长期目标是了解地球表面条件下的基本地球化学，矿物学和地球生物学过程，并将这些知识应用于应对环境挑战。本研究包括三个主题：（1）CO2在矿山废物中的封存，（2）天然模拟CO2封存，（3）尾矿风化和胶结。** 尾矿的风化可导致碳酸盐矿物的形成，这些矿物可储存二氧化碳，这是一种关键的温室气体。通过这一过程，某些矿山有能力抵消采矿的温室气体排放，但需要开发技术以利用这一能力（主题1）。在加拿大、南非和博茨瓦纳的矿山进行的实地工作将确定CO2封存能力，而实验室实验将确定尾矿中CO2封存的程度和速度。对与尾矿成分相似的岩石的自然风化的研究将提供有关地球表面化学风化的驱动因素和限制的见解，这些化学风化调节了地质时期大气中的CO2浓度（主题2）。最后，将在实验室研究尾矿中的有益风化过程（主题3）。这些过程包括通过矿物沉淀进行胶结和表面钝化，有助于限制金属释放并提高尾矿稳定性。** 拟议的研究将促进我们对碳循环，风化和矿山废物管理的理解，同时培训新一代科学家来解决紧迫的环境问题。学生将获得知识和技能，以启动他们的职业生涯，并成为他们所选择的领域的领导者。这项研究将为矿产资源的可持续发展做出重大贡献，并设计新的二氧化碳封存工艺，以促进社会向低碳经济过渡。研究成果将有助于指导矿业公司利用其矿物废物减少温室气体排放，限制碳定价成本，改善尾矿管理，并有利于其社会许可证的运营。开发和实施减少温室气体排放的新技术将为加拿大人在新兴的碳管理和固碳部门创造就业机会。

Carbon management and sequestration are emerging areas in geoscience research that are motivated by concerns over the impacts of climate change, and the increasing financial incentives of carbon pricing. Contemporaneous to the need to reduce greenhouse gas (GHG) emissions, the generation of mine wastes, such as tailings (fine-grained waste rock), is escalating due to the increasing demand for resources. Consequently, the mining industry must develop more secure and cost-effective tailings management practices while improving environmental performance. The long-term goal of the proposed research is to understand fundamental geochemical, mineralogical, and geobiological processes at Earth's surface conditions and apply this knowledge to address environmental challenges. This research comprises three themes: (1) CO2 sequestration in mine wastes, (2) natural analogues for CO2 sequestration, and (3) tailings weathering and cementation. ******Weathering of mine tailings can result in the formation of carbonate minerals that store CO2, a key GHG. Through this process, certain mines have the capacity to more than offset the GHG emissions of mining, yet technologies need to be developed to take advantage of this capacity (Theme 1). Fieldwork conducted at mines in Canada, South Africa, and Botswana will determine CO2 sequestration capacities, while laboratory experiments will determine the extent and rates of CO2 sequestration within mine tailings. Study of natural weathering of rock with similar composition to the mine tailings will provide insights regarding the drivers and limitations of chemical weathering at Earth's surface that regulates atmospheric CO2 concentrations over geologic time (Theme 2). Lastly, beneficial weathering processes in tailings will be studied in the laboratory (Theme 3). These processes include cementation and surface passivation through mineral precipitation that can help limit metal release and improve tailings stability. ******The proposed research will advance our understanding of carbon cycling, weathering, and mine waste management while training a new generation of scientists to tackle pressing environmental issues. Students will acquire the knowledge and skills to launch their professional careers and become leaders in their chosen field. This research will make major contributions to the sustainable development of mineral resources and devise novel processes for CO2 sequestration to facilitate society's transition to a low-carbon economy. Research outcomes will help guide mining companies to utilize their mineral wastes to reduce GHG emissions, limit the costs of carbon pricing, improve tailings management, and benefit their social license to operate. Developing and implementing new technologies for reducing GHG emissions will create employment opportunities for Canadians in the emerging sectors of carbon management and sequestration.