Preparation method and application of biochar-steel slag composite adsorption material

Abstract

The invention discloses a preparation method of a biochar-steel slag composite adsorption material, which specifically comprises the following steps: mixing steel slag with biochar, and carrying out hydrothermal uniform mixing and pyrolysis sintering to obtain a product. The method comprises the following specific steps: S1, respectively crushing the steel slag and the biochar into small particles; s2, mixing the small steel slag particles with the small charcoal particles; s3, putting the small particles obtained in S2 into a reaction container, adding deionized water, and uniformly stirring; s4, putting the reaction container in the S3 into a water bath, and evaporating to dryness; s5, putting the reaction container into a pyrolyzing furnace, introducing N2 into the pyrolyzing furnace, exhausting air, and then increasing the temperature of the pyrolyzing furnace; s6, after the pyrolysis is finished, continuously introducing N2 into the pyrolyzing furnace until the pyrolyzing furnace is cooled to room temperature; and S7, collecting a product. No additional agent is needed in the preparation process, the process complexity and energy consumption are reduced, and raw materials are saved; the adsorption capacity and the adsorption stability are improved, and the adsorption equilibrium time is shortened; and the steel slag and the biomass material are recycled.

Description

technical field [0001] The invention belongs to the technical field of heavy metal sewage treatment, and in particular relates to a preparation method and application of a biochar-steel slag composite adsorption material. Background technique [0002] Steel slag refers to the solid waste slag discharged during the steelmaking process, and about 8% to 15% of steel slag is produced for every 1 t of crude steel produced. According to data from the China Scrap Iron and Steel Application Association, in 2018, China's steel slag emissions were as high as 120 million tons. From the early 1990s to the end of 2018, the accumulated stockpiles of steel slag tailings in China exceeded 1.8 billion tons. There are various types of steel slag. In addition to the converter steel slag discharged from the converter steelmaking process, there are other electric furnace steel slag discharged from the electric furnace steelmaking process and stainless steel slag discharged from the stainless st...

AI Technical Summary

Problems solved by technology

However, the modification process needs to consume a large amount of chemicals or energy, and the economical practicability is poor, which is an important reason why it is not used in industrialization

[0006] The traditional high-temperature pyrolysis method consumes too much energy: the high-temperature pyrolysis method is the most traditional and mature preparation method, which is to react biomass raw materials in a high-temperature furnace in an oxygen-free or low-oxygen state to obtain Preliminary biochar (also known as pyrolytic char), while biochar prepared in this way consumes a lot of energy and is affected by heating temperature and heating rate, that is, at lower temperature and slower heating rate will promote biochar But the temperature is too low will lead to incomplete carbonization, carbonization time is too long

[0007] The adsorption performance of biochar is limited: the raw materials of biochar come from a wide range of sources, and the surface properties of charcoal are also affected by the preparation process, so its adsorption performance varies. poor performance for

[0008] The adsorption performance of steel slag is limited: steel slag mainly relies on electrostatic interaction to selectively adsorb heavy metal ions, so the adsorption stability is poor, and the composition of steel slag from different origins is quite different

The adsorption efficiency of steel slag is not high due to the influence of its own physical and chemical properties, and there are still problems in its wide industrial application as an adsorbent

[0009] Poor particle size uniformity of steel slag: The particle size of steel slag recovered from iron and steel smelting enterprises is uneven, the processing efficiency is not high, and the ability to adsorb and fix heavy metals is poor

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