This document provides oil sands mining operators with guidelines for the audit and assessment process consistent with the requirements set out in the Performance Management documents from COSIA. There is a requirement for a 5-year audit and assessment by an independent team of audit/assessors. Through this process, the audit and assessment team will: 1. Assess the reasonableness of the relevant plans and reports. 2. Provide an opinion as to whether the mine closure plan is realistic and the progressive management of FFT is on track to the desired closure outcome.
Quote from main page: A Guide to the Management of Tailings Facilities (the Tailings Guide) is designed to be applied by MAC members and non-MAC members alike, anywhere in the world. The Tailings Guide, first released in 1998, provides guidance on responsible tailings management, helps companies develop and implement site-specific tailings management systems, and improves consistency of application of engineering and management principles to tailings management.
In 2012, SIMEC Mining commenced a detailed investigation into changing the way the magnetite tailings storage facility (Mag TSF) operates at the South Middleback Ranges (SMR) to increase water recovery and provide a sustainable cost-base for tailings management. Changes were also necessary to support the Magnetite Expansion Project (MEP) that was destined to be commissioned in October 2013. A feasibility study was performed with Golder Associates to understand the technical and commercial influences and provide a capital estimate for several options. The selected option from the study was a redesign of the current dual discharge TSF to a perimeter discharge, central decant (PDCD) design. Application of Nalco WaterShed polymer at the Big Baron Pit (Verdoornet al. 2018) revealed the technology would greatly assist in the successful conversion of the TSF to a PDCD configuration. Expectation was high that WaterShed polymer treatment would allow greater beach angle control, improved water recovery, and a reduction in surface water pooling across the TSF with water pooling concentrated around the central decant allowing for efficient removal prior to loss via evaporation or seepage. A conceptual design for the polymer tailings dewatering application was developed in collaboration with Nalco Water and dosing commenced in October 2013. Due to unknown risks associated with dewatering magnetite tailings, the project was split into two stages, namely, phase 1: a proof of concept trial to establish the applicability of Watershed on the magnetite tailings prior to commissioning of MEP; and phase 2: fully operationalise the PDCD configuration. Golder was engaged to develop a life-of-mine plan for the TSF at SMR that could be safely operated to a planned final height of RL 199 m. Throughout 2013 and 2014, design and construction occurred to convert the Mag TSF to a PDCD facility. A master plan was developed to manage tailings storage for five years from March 2014, referred to as the First 5 Year Plan. This involved six wall raises that would eventually fill the three voids near the western embankment and bring the height of the TSF to RL 172 m. The civil concept selected was based on an alternatives assessment that presented three options. SIMEC Mining chose the lowest cost approach of filling the voids with WaterShed polymer treated tailings to provide a base for 3 m wall raises upstream. Strict deposition and water recovery models were followed to ensure sufficient dewatering and the subsequent drying of the tailings layers. There was also extensive test work completed prior to each of the individual embankment raises to ensure that the dewatered tailings had the appropriate density and strength properties to support the raises before commencing with the lifts. During the first five years of operation, water recovery was around 60% and the volume utilisation was in line with the deposition model. The high percentage of water recovered enabled the processing plant to reach its new design capability, reduce significant downtime due to water availability and provide the mining operations with sufficient water for dust suppression. The second five-year plan is currently being finalised and progress is consistent with the tailings deposition and the dewatering model.
Dr. Robertson's technical papers on Cone Penetration Testing (CPT) and liquefaction
Estimating the in situ state that will be achieved within a thickened tailings storage facility is often challenging, as laboratory-prepared specimens are known to not necessarily reproduce the fabric and density of the tailings when they settle under full-scale high energy deposition. Samples prepared in the laboratory from non-segregating slurries often result in quite dense states, which may not occur in full-scale deposition. Some of these issues were investigated during a recent geotechnical investigation of a thickened tailings deposit. The investigation consisted of cone penetration test (CPT) probes followed by piston samples at locations directly adjacent to the probes within saturated regions near the base of the tailings. The piston samples were used to estimate in situ density by means of gravimetric water content (GWC) of the entire sample, and to provide material for preparing loose, moist tamped, reconstituted samples for measuring the critical state line (CSL) of the recovered tailings. The resulting state indicated by comparing the in situ GWCs and the CSLs agreed well with that inferred by CPT-based methods, providing additional confidence in both techniques. A reconstituted sample prepared as a slurry in the lab exhibited a denser state than that indicated from in situ GWCs, raising questions about the accuracy of laboratory-prepared slurries for investigating the density likely to be achieved in situ.
While not specific to tailings, this webinar includes valuable knowledge for tailings engineers. At a loss when hydrologists and hydrologic engineers start throwing out fancy terms like flood return interval, antecedent moisture condition, initial abstraction, etc.? As a professional working with these technical individuals and their reports, it is essential that you fully understand where they are coming from so that you can be a productive participant in a project with a hydrologic component. This webinar explores the concepts, terms, and analyses behind hydrology, and the basis of the analyses that goes into hydrologic studies. It teaches you how to find sources for hydrologic data and how to read the data from hydrographs.
Mineral development is an important land use within the BLM's multiple-use mandate. In communities across the country, mining provides jobs, economic activity and important commodities that are essential to maintain a high quality of life. This website discusses the mining and mineral processes under the purview of the BLM.
The paper summarizes data on a tailings dam and performance during its service life. An expected increase in reservoir level required a complete assessment of dam stability. The assessment involved a comprehensive geotechnical investigation. The results of the geotechnical investigation and analysis to evaluate current conditions and predict future dam behavior are presented and discussed.
Copy of workshop presentation. Snow presents state programs requiring PE certifications, Montana EOR Requirements for TSF, Federal Programs Requiring PE Certification, the MSHA initiative, and Surface Mining Control and Regulation Act regulatory program.
Fairbanks Gold Mining, Inc., (FGMI) a subsidiary of Kinross Gold operates the Fort Knox mine and mill, located 26 miles northeast of Fairbanks, Alaska. The average daily temperature in the Fairbanks district rises above freezing in late April and drops below freezing in early October. Mid winter temperatures can easily reach -50° F with the average maximum temperature remaining below zero through December and January. These arctic conditions have created discontinuous permafrost that covers much of the north facing slopes in the region. Unique challenges were encountered due to the permafrost conditions in addition to the extreme cold temperatures of the arctic region that affected the design, construction, and operation of the tailings impoundment. Permitting of the impoundment included an Environmental Assessment with the Corp of Engineers as the lead agency and a permitting team concept with all affected agencies participating in permitting decisions. Mitigation measures have been implemented to offset the wetlands impacted by the tailings impoundment construction and operation and include development of additional wetlands, habitat enhancement, and a water storage reservoir.