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，在1948年至2004年的56年运营期间，是加拿大最大的金矿之一。在前运营商破产后，giant矿区的所有权和修复责任恢复到加拿大联邦政府，与该矿区相关的100亿美元的责任完全由加拿大纳税人承担。巨型金矿的浸染金与含砷黄铁矿（FeAsS）的矿石有关，矿石经过焙烧，从硫化基质中释放出金。这个过程产生了三氧化二砷焙烧废物。大约237,000吨三氧化二砷焙烧废料被堆放在巨人矿场的采场和地下专门建造的硐室中。一个关键的挑战是制定和实施一项可行的长期解决方案，以稳定和管理三氧化二砷焙烧机废物。本研究计划的总体目标是确定长期稳定和储存砷-三氧化剂废物的潜在策略。拟议的NSERC联盟项目是与巨人矿山监督委员会合作开展的，以现有的研究工作为基础，重点关注巨人矿山的补救措施，以制定和评估管理焙烧炉废物的战略。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)三氧化砷废物的化学和物理特性；通过2)砷酸铁沉淀、3)高温硫化、4)生物硫化、5)玻璃化、6)加入水泥膏体回填来稳定三氧化二砷焙烧废物；7)应用非传统同位素系统了解三氧化二砷焙烧废物转化的生物地球化学反应机制。这一研究方案的结果将有助于制定一项永久性和安全的战略，以便在巨人矿场和产生砷废物的其他金矿对三氧化二砷焙烧废物进行补救。

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.