SYNTHESIS OF GEOTECHNICAL PROPERTIES OF MINE TAILINGS
Open Access
- Author:
- Wang, Yen Chieh
- Graduate Program:
- Civil Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- April 15, 2019
- Committee Members:
- Ming Xiao, Thesis Advisor/Co-Advisor
Tong Qiu, Committee Member - Keywords:
- mine tailings
coal slurry
mineral properties
coefficient of consolidation - Abstract:
- Minerals and their products play a vital role in human’s life after the 19th Century. In 2015, the value of coal, metals, and industrial minerals mined in the United States was over $100 billion according to the report of U.S Geological Survey (USGS). Tailings dams that are usually used to store these wastes encountered several structural failures in the past century. These catastrophes not only affect human’s life but also pollute the environment. Recently, an iron tailings dam failure in Brazil on Feb 1, 2019 caused more than 60 deaths and significant economic loss. This study synthesizes the data that were presented in the previous publications in last 40 years along with the coal tailings data that were obtained by the Penn State (PSU) research team. This thesis compared the basic geotechnical properties of different mineral tailings and derived correlations of these properties. The results indicate that fine and coarse coal tailings tend to have lower specific gravity than other minerals. Most of the classifications of fine coal tailings belong to CL and ML. Copper tailings generally have higher hydraulic conductivity than gold tailings. Compared with other mineral tailings, fine coal tailings have the lowest hydraulic conductivity. This study also found that for fine coal tailings the percentage of clay size particles has higher impact on PI than fine content. The percentage of clay size particle and fine content, on the other hand, have very similar impact on LL. A relationship equation between fine content and coefficient of consolidation of fine coal tailings that are classified as SM or ML was derived in this study. The collected database showed that most of the mineral tailings still lack information in both basic properties (i.e. liquid limit and plastic index) and advanced laboratory testing. Even the existing data showed high variability. Compared to the large amount of usage in minerals, the information of mineral tailings is still very limited.