Investigation of cellulose filament for mine backfill

矿山回填已逐步融入地下采矿作业，以增加矿石提取率，提高地下稳定性，并处理矿山废弃物。在这一过程中，由沉淀物/尾矿悬浮物组成的矿物开采废物流与增强剂（通常是水泥）混合，然后泵回地下，重新填充它们被移除的区域。各种类型的矿山充填体，如膏体充填体或凝胶充填体，已经开发出来，以满足各种采矿作业的具体需要。为了优化采矿技术，需要提高充填体的物理力学性能。高强度矿山充填体可用于为现有隧道网络提供结构支撑，从而在给定区域内增加采掘量。因此，提高充填体的强度对提高采矿作业的总产量是有用的。本课题将首次测试高纤化纳米纤维素材料稳定和改善矿山充填体结构性能和流变性能的能力。在这项研究中使用的纳米纤维素是通过最近开发的高稠度精炼工艺生产的，并且已经适应和定制了各种不同的工业应用。生产这种纳米纤维化纤维素的技术最近获得了Performance BioFilaments公司的许可。这种纳米纤维化纤维素的高长宽比（长宽比），以及其高度的柔韧性和特殊的表面积，使其成为缠绕和结合尾矿颗粒的理想材料。预计纳米纤化纤维素材料在作为粘合剂补充或替代水泥材料（全部或部分）时，也将提高矿山回填体的强度和流变性能，从而减少采矿业的总体碳足迹。如果成功，本研究将增加公司的竞争力，并将有助于公司扩大其产品在采矿业的潜在应用，并产生更多的收入。

Mine backfill has been progressively integrated into underground mining operations to increase ore extraction,improve underground stability, and to dispose of mine waste material. In this process, waste streams frommineral extraction comprising suspensions of sediments/tailings are mixed with a reinforcing agent (oftencement), then pumped back underground to refill the areas where they were removed from. Various types ofmine backfill such as paste fill or Gel fill have been developed to address the specific needs of various miningoperations. For optimization of mining techniques, mine fill with improved physical and mechanical propertiesare desirable. Higher-strength mine fill can be used to provide structural support to existing tunnel networks,allowing for increased extraction within a given area. Improving the strength of the backfill is therefore usefulfor enhancing the overall yield of a mining operation.In this proposal, a highly-fibrillated nanocellulosic material will be tested for its ability to stabilize and improvethe structural performance and rheology of mine backfill for the first time. The nanocellulose to be used in thisresearch is produced via a high-consistency refining process that was recently developed and has since beenadapted and tailored for a variety of different industrial applications. The technology for producing thisnanofibrillated cellulose was recently licensed by Performance BioFilaments Inc. The very high aspect ratio(ratio of length to width) of this nanofibrillated cellulose, along with its high degree of flexibility andexceptional surface area, make it an ideal material for entangling and binding-together tailing particles. It isexpected that the nanofibrillated cellulose material will also improve the strength and rheology performance ofmine backfill when it is used as binder to complement or replace cement material (either totally or partially),and thus reduce the overall carbon footprint in the mining industry. With success, this study increases thecompetitiveness of the company, and will aid the company's intention to expand the potential applications of itsproduct to mining industry, and generate more revenues.