Analysis on Physical and Mechanical Properties of Red Mud Materials and Stockpile Stability after Dilatation

Yanbo Feng,Chao Yang

doi:10.1155/2018/8784232

Abstract

Red mud is the tailings generated from the production process of aluminum industry and is mainly stacked in open-air at present, so how to ensure the stability of red mud stockpile is very important. Regarding mud stockpile of Guizhou Aluminum Factory as the research object, this paper studies the physical and mechanical properties of Bayer red mud from wetting process, Bayer red mud from drying process, and sintering red mud through laboratory test and finally analyzes its stability under extreme rainfall condition in this region by the Geo-Studio software. The research results show that the red muds in different processes have big difference in physical and mechanical properties. The strength of sintering red mud is about 4.2 times of that of Bayer red mud from wetting process on average, and the strength of Bayer red mud from drying process is about 1.5 times of that of Bayer red mud from wetting process on average. So, the sintering red mud can be used as the subdam of red mud stockpile, to reduce the risk of collapse and dam break. The stability coefficients of the mixed stocking method under three rainfall conditions are 2.611, 2.597, and 2.631, respectively, all of which are above 1.0. It reveals that the dilatation scheme of using the sintering red mud with good engineering properties to stockpile the Bayer red mud is feasible. It can not only guarantee the safety and stability of red mud stockpiles, but also reduce the risk of red mud dam break and the capital investment of red mud yard.

Highlights

Red mud is the tailings generated from the production process of alumina in aluminum industry
To analyze the stability of red mud stockpile under rainfall condition, this paper firstly studies the physical, microscopic, and mechanical properties of three kinds of red mud (Bayer red mud from wetting process, Bayer red mud from drying process, and sintering red mud) by the laboratory test. e detailed test scheme is as follows
According to relevant provisions of Method for Chemical Analysis of Clay [21], three kinds of red mud are dried at 105°C till the constant weight and sifted by 200-mesh sieve after grinding. e chemical components and mineral compositions of red mud are analyzed and tested by X-ray fluorescence spectrometer (XRF) and X-ray diffractometer (XRD). e samples are broken into the relatively regular blocks of 1 cm3

Summary

Introduction

Red mud is the tailings generated from the production process of alumina in aluminum industry. Us, the resource utilization of red mud attracts the universal attention and comparatively deep research, and achievements have been made, such as extraction of valuable metal, and preparation of building materials or adsorbing materials [3,4,5]. Bayer red mud has fine particles, engineering properties similar to silty clay, high water content, poor permeability, low shear strength, and long consolidation time [9]. Guizhou Aluminum Factory adopts the “wetting process” to stack the Bayer red mud for 40 years since putting into production, and the reservoir capacity fails to meet the requirements. The physical, microscopic, mechanical, and hydraulic characteristic parameters of red mud in this yard are obtained through the laboratory test, the design scheme of yard dilatation is put forward based on relevant experience of similar engineering, and the stockpile stability after dilatation under different rainfall conditions is calculated and analyzed. e conclusion can provide some reference for design and construction of similar engineering

Engineering Overview and Yard Dilatation Scheme

Physical and Mechanical Properties of Red Mud

Test Results

Stockpile Stability Calculation of Red Mud in Mixing Stack

Conclusions