Abstract
Sulfide minerals (mainly FeS2) contained in lead-zinc tailings are easy to be acidified in the air. The acidification mechanism is that the tailing sand generates sulfuric acid and sulfate under the catalysis of oxidant, water and oxygen. The acidic liquid generated by the reaction will continue to react with metal oxides to form an insoluble precipitate.In order to reveal the corresponding changes of chemical properties and physical properties of lead-zinc tailing sand during acidification, a series of reaction processes of tailings under natural conditions were simulated by immersion test in laboratory.It is found through the test that with the deepening of acidification, the coarse particles of tailing sand dissolve, resulting in the decrease of iron concentration in the compound, the increase of fine particles, the increase of specific surface area, the decrease of surface friction and occlusion friction between particles, resulting in the decrease of internal friction angle, and the decrease of the safety of tailings dam. words.
Highlights
The introductionIn the development and utilization of mineral resources rich in metal sulfide, tailings produced by mining and dressing are one of the main solid wastes.The most common sulfide in tailings is pyrite, and the acidification of pyrite leads to the migration of thallium and toxic heavy metal ions to the environment, causing pollution to groundwater and soil[1].The acidic waste liquid produced by the acidification of tailings will corrode the dam body of tailings dam and affect the long-term stability of tailings dam
X-ray fluorescence spectroscopy (XRF) scanning analysis of the samples showed that the lead-zinc tailing sand used in this study was mainly composed of pyrite (FeS2), silica (SiO2), calcium oxide (CaO) and so on
Pyrite is oxidized under natural conditions, and the recovery rate of pyrite will decrease with the extension of oxidation time[6].The highest content of sulfide in leadzinc tailings used in this study is FeS2, which is oxidized under natural conditions.Under natural conditions, FeS2 will react under the catalysis of oxidizing bacteria, water, oxygen, ferric ion, etc
Summary
In the development and utilization of mineral resources rich in metal sulfide, tailings produced by mining and dressing are one of the main solid wastes.The most common sulfide in tailings is pyrite, and the acidification of pyrite leads to the migration of thallium and toxic heavy metal ions to the environment, causing pollution to groundwater and soil[1].The acidic waste liquid produced by the acidification of tailings will corrode the dam body of tailings dam and affect the long-term stability of tailings dam. Scholars at home and abroad have made some exploratory studies on the acidification of tailings.Zhan Jing et al [2] found that plant litter can effectively reduce the acidification degree of tailings, and when combined with alkaline substances like lime, it can slow down the acidification of tailings, and increase the nutrient accumulation of tailings, which is conducive to the realization of ecological restoration.Liang Bing et al.[3,4] carried out an experimental study on the influence of acid-base solutions with different pH values on the compression characteristics and permeability characteristics of tailing sand.Sulfide tailings rich in carbonate may be acidified and produce a large amount of heavy metal pollution[5].Analysis of previous research, in view of the tail sand acidizing result in physical and mechanical properties changes mainly pauses in the macro level is only for PH this change were analyzed, and no in-depth analysis of the mechanism of acidizing, and the mechanism of acidification and tail ore material composition, structure and the change rule of physical and mechanical properties,So this research by conducting dynamic immersion, direct shear, consolidation, screening, bet specific surface area determination, icp iron, xrf, element analysis and a series of test research on the tail sand under different degree of oxidation - acidification mineral composition, size distribution, the change of the chemical, physical and mechanical properties such as density, and explore the relationship between the chemical and physical ways
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
