Remediation Strategies for the Long-term Management of Arsenic-trioxide Roaster Waste at the Giant Mine, Northwest Territories

巨型金矿位于西北地区的耶洛奈夫，从1948年到2004年运营了56年，是加拿大最大的金矿之一。在前运营商破产后，巨人矿场的所有权和补救责任恢复到加拿大联邦政府手中，与该矿场相关的10亿美元债务完全由加拿大纳税人承担。巨矿中分散的金与含毒砂(FeAsS)矿石伴生，矿石经焙烧后从硫化物基质中解离出金。这一过程产生了三氧化二砷焙烧废物。约237,000吨三氧化二砷焙烧废料被存放在Giant矿址地下的采空区和专门建造的矿房中。一个关键的挑战是制定和实施一个可行的长期解决方案，以稳定和管理三氧化二砷焙烧废物。这项研究计划的总体目标是确定长期稳定和储存三氧化二砷废弃物的潜在战略。拟议的NSERC联盟计划是与巨人矿监督委员会合作进行的，建立在现有研究工作的基础上，重点是巨人矿的修复，以制定和评估管理焙烧废物的战略。该联盟计划包括七个有针对性的研究项目，以应对这一挑战，包括：1)三氧化二砷焙烧炉废物的化学和物理特征；2)砷酸铁沉淀，3)高温硫化，4)生物硫化，5)玻璃化，6)并入胶凝膏体回填；以及7)非传统同位素系统的应用，以了解促成三氧化二砷焙烧炉废物转化的生物地球化学反应机理。这项研究计划的结果将有助于制定一项永久性和安全的战略，以修复巨人矿场和其他产生砷废物的金矿的三氧化二砷焙烧废物。

The Giant Mine, located in Yellowknife, Northwest Territories, was one of the largest gold mines in Canadaduring its 56 years of operation from 1948 until 2004. Ownership and responsibility for remediation of theGiant Mine site reverted to the Federal Government of Canada following the bankruptcy of the formeroperator, and the > $1B liability associated with this site is entirely borne by Canadian taxpayers. Disseminatedgold at the Giant Mine was associated with arsenopyrite (FeAsS)-bearing ore, which was roasted to liberate thegold from the sulfide matrix. This process generated an arsenic-trioxide roaster waste. Approximately 237,000tonnes of arsenic-trioxide roaster waste was deposited in mined-out stopes and purpose-built chambersunderground at the Giant Mine site. A critical challenge is the development and implementation of a viable,long-term solution for stabilizing and managing the arsenic-trioxide roaster waste. The overall goal of thisresearch program is to identify potential strategies for long-term stabilization and storage of arsenic-trioxideroaster waste. The proposed NSERC Alliance program, conducted in partnership with the Giant MineOversight Board, builds on existing research efforts focused on remediation of the Giant Mine to develop andevaluate strategies for managing the roaster waste. This Alliance program includes seven targeted researchprojects to address this challenge, including: 1) chemical and physical characterization of the arsenic-trioxideroaster waste; arsenic-trioxide roaster-waste stabilization through 2) precipitation of iron arsenates, 3) high-temperature sulfidation, 4) biogenic sulfidation, 5) vitrification, and 6) incorporation into cemented-paste backfill; and 7) application of non-traditional isotope systems for understanding the biogeochemical reaction mechanisms which contribute to transformation of arsenic-trioxide roaster waste. The results of this research program will contribute to the development of a permanent and safe strategy for remediation of arsenic-trioxide roaster waste, both at the Giant Mine site and other gold mines where arsenical wastes are generated.