Investigation of cellulose filament for mine backfill

矿山回填已逐步整合到地下采矿作业中，以增加矿石开采量，提高地下稳定性，并处理矿山废料。在这一过程中，矿物开采产生的含有沉积物/尾矿悬浮液的废物流与增强剂（水泥硬化剂）混合，然后泵回地下，重新填充它们被清除的地区。各种类型的矿山回填，如膏体充填或凝胶充填已开发，以满足各种采矿作业的特定需求。为了优化采矿技术，需要具有改善的物理和力学性质的矿山充填物。较高强度的矿山充填物可用于为现有隧道网络提供结构支撑，从而增加给定区域内的开采量。因此，提高回填土的强度对于提高采矿作业的总体产量是有用的。在本提案中，将首次测试高度原纤化的纳米纤维素材料稳定和改善矿山回填土的结构性能和流变性的能力。本研究中使用的纳米纤维素是通过最近开发的高稠度精制工艺生产的，该工艺已被适应和定制用于各种不同的工业应用。生产这种纳米原纤化纤维素的技术最近获得了Performance BioFilaments Inc.的许可。这种纳米原纤化纤维素的非常高的纵横比（长度与宽度的比率），沿着以其高度的柔性和超表面积，使其成为用于缠结和结合在一起的尾矿颗粒的理想材料。预计纳米原纤化纤维素材料还将在其用作粘合剂以补充或替代水泥材料（全部或部分）时改善矿山回填的强度和流变性能，从而减少采矿业中的总体碳足迹。随着这项研究的成功，提高了公司的竞争力，并将有助于公司的意图，扩大其产品的潜在应用到采矿业，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.