Research of the possibility of processing MSW combustion slag into complex mineral fertilizers

Abstract

In addition to the global environmental catastrophe due to natural reasons, industrial emissions, including waste from mining, society is concerned about the process of accumulation of solid domestic waste (MSW), which inevitably accompanies the life of people. Researchers are focusing their efforts on finding ways to use waste as secondary raw materials. Among the technologies that contribute to the utilization of solid waste, they consider their use as a raw material for the production of complex fertilizers. The article is devoted to the study of the possibilities of using waste from the local industry and natural resources of Azerbaijan to improve the efficiency of the country's agro-industrial sector. The slag of the MSW processing plant was used as a raw material, with the addition of phosphogypsum and local natural formation of dolomite as modifiers. The refining process was carried out with dilute sulfuric acid obtained from the waste of an oil refinery. The influence of technological parameters of sulfuric acid processing of raw materials on the characteristics of the obtained complex fertilizer has been studied. The preferred order of introduction of reagents into the processing process has been determined. By varying the ratio of the components of raw materials, the concentration of sulfuric acid, the temperature range and the time of the process, the optimal processing conditions were determined. It was found that the optimal conditions within the considered limits of processing the selected raw materials can be considered the use of 10% H₂SO₄, at a temperature of 40 – 50°C for 20 minutes. The role of MSW slag and the effect of amount of dolomite introduced into the composition of raw materials to increase the mechanical strength of the resulting complex fertilizer has been substantiated.