Long-acting evaluation method for active magnesium oxide solidified/stabilized zinc-containing smelting slag based on carbonation accelerated exposure

Abstract

The invention discloses a long-acting evaluation method for active magnesium oxide solidified / stabilized zinc-containing smelting slag based on carbonation accelerated exposure. The long-acting evaluation method comprises the following steps: adding active magnesium oxide to carry out solidification / stabilization treatment on the zinc-containing smelting slag, and maintaining; the method comprises the following steps: preparing saturated CO2 water, measuring the pH value, carrying out accelerated carbonation continuous extraction on zinc-containing smelting slag after active magnesium oxide treatment and untreated zinc-containing smelting slag, and measuring the pH value, the conductivity, the magnesium ion concentration and the zinc ion concentration of an extract liquid; based on the change rule of pH, conductivity and magnesium ions in the leaching solution, determining the number of times of accelerated carbonation leaching; and based on the corresponding relation between the average concentration of the accumulated leaching liquid zinc and the accumulated carbonic acid exposure, the endurance capacity of the repaired slag body to carbonic acid is evaluated. According to the method, an accelerated carbonation exposure test is designed, key environmental factors influencing the release behavior of zinc in the active magnesium oxide solidified / stabilized zinc-containing smelting slag are considered, and the long-term activation risk of zinc in the smelting slag after solidification / stabilization repair is systematically evaluated.

Description

technical field [0001] The invention relates to the research field of harmless treatment of solid waste, in particular to a long-term evaluation method for solidified / stabilized zinc-containing smelting slag based on carbonation accelerated exposure. Background technique [0002] my country is the main producer of zinc concentrate in the world. During the high-temperature smelting process, the slag discharged from the zinc ore will be quenched by water to produce a large amount of zinc-containing smelting slag, which mainly exists in the form of glass phase and has potential hydraulic activity. With the rapid development of the zinc metallurgical industry, the production of zinc-containing smelting slags in my country is huge and the utilization rate is relatively low. Therefore, there are disorderly accumulations of zinc-containing smelting slags in many occasions, and the release of heavy metals such as zinc leads to high environmental risk. [0003] Solidification / stabili...

AI Technical Summary

Problems solved by technology

However, long-term carbon dioxide carbonation may affect the release performance of heavy metals in zinc-containing slags

Carbon dioxide carbonation can reduce the leaching of heavy metals and increase the compressive strength of the solidified body by changing the mineralogy structure of the cement hydration reaction product; however, carbon dioxide carbonization can also easily lead to a decrease in the buffering capacity of the solidified body and a change in mineralogy. May accelerate the release of heavy metals

However, the long-term monitoring method is time-consuming and labor-intensive, and is restricted by the disposal scenarios after smelting slag restoration. In many cases, on-site monitoring cannot be carried out.

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