-
Date submitted2022-10-31
-
Date accepted2023-04-21
-
Date published2024-02-29
Study of the properties and action of polyelectrolytes in the treatment of the dressing plant’s discharges
The organization of intrafactory water circulation at mining and processing enterprises, when production wastes and discharges are not sent to an external tailings dump, is an urgent environmental and economic task. Returning even a part of water into the technological process after preliminary treatment will significantly reduce the volume of polluted water discharged into tailings, which will reduce energy costs for waste transportation and the negative environmental impact. One of the wastes sent to the tailings during the ore dressing wastes from the Kovdor deposit to the tailings dump is the discharge of thickeners for the preparation of apatite flotation feed. In order to choose the effective discharge cleaning regime, the authors have evaluated the action of polyacrylamide flocculants. It has been discovered that the apatite and calcite particles interact more effectively with the anionic flocculant. This fact determines its advantage for the treatment of suspended particles. The influence of the residual concentration of a flocculant on the apatite flotation, where a part of the returned treated water goes, has been assessed. Compared to flotation with recycled water, there is a decrease of P2O5 extraction into apatite concentrate of equal quality. In order to obtain the required enrichment indicators on the treated water, it is necessary to adjust the collector (tall oil fatty acids) and depressor (liquid glass) costs.
-
Date submitted2019-08-08
-
Date accepted2019-09-16
-
Date published2020-02-25
Testing of preformed particles polymer gel technology on core filtration models to limit water inflows
In order to reduce watering of wells and equalize their injectivity profiles, the prospects of introducing PPG technology in Russian fields are considered, in which preformed particles polymer gel are pumped into the injection well. These particles, being a supersorbent based on polyacrylamide, absorb water, become elastic, which allows them to shrink and tear in narrow filtration channels. When the polymer is filtered along permeable layers saturated with water, polymer particles accumulate in waterlogged intervals and thus they form a polymer plug, which redistributes the filtration flows and increases the coverage of the formation by the process of oil displacement. More than 4000 downhole operations have been carried out in the fields of China and the USA using PPG technology by now. In domestic fields in Western Siberia, there is limited experience in applying a similar technology in high-temperature formations with low mineralization of formation water. Due to the absence of hydrolytic processes in polyacrylamide, well-known domestic compositions are not applicable due to the low absorption capacity in the conditions of low-temperature deposits with increased mineralization of formation water. The authors synthesized a polymer based on polyacrylamide by block polymerization, which allows to obtain a high absorption capacity, including for low-temperature formations with high mineralization of formation water, which is typical for Perm Territory fields. Filtration experiments were carried out on core models with the composition developed by the authors, this composition focused on low formation temperatures and high mineralization of formation water. As a result of the experiments, it was found that the swollen particles of the gel are able to pass into fractures with a diameter less than their own size at least 20 times. With a significant increase in the viscosity of the dispersion medium, the stability of the suspension increases. Particles of polymer gel have the necessary strength for injection in the field conditions. The fracture permeability during polymer injection decreases by several times and becomes comparable with the permeability of pore collectors.