Characterization Of Magnetic Composite Adsorbent Prepared From Laterite Nickel Ore And Its Adsorption Mechanism For Chromate Ions

The traditional process produces a large amount of electric iron nickel smelting waste slag,and its stacking and landfilling not only cause environmental pollution but also occupy a large area.At the same time,some industrial sewage was discharged illegally,causing great losses to people’s lives and property.According to incomplete statistics,the water pollution rate is as high as 80%.Among them,the problem of heavy metal pollution is particularly prominent.Chromium compounds often pollute the environment in the form of aqueous solutions and inhibit the self-purification effect of water bodies.t can enter the body through water and food and cause health hazards.Hexavalent chromium is 500 times more toxic than trivalent chromium.It is more easily absorbed by the human body and can accumulate in the body.It can cause damage to the internal tissues of the human body.The main content of the thesis is as follows:First,nickel-iron extract was obtained by ammonium sulfate roasting-leaching process using laterite nickel ore as raw material;magnetic core was prepared by hydrothermal method using nickel-iron extract;sodium silicate solution was prepared by using laterite nickel ore slag,Coating experiment to prepare composite adsorption materials.Characterize their morphology and structure,such as SEM,XRD,and VSM.The adsorption properties of acid ions were studied.Secondly,the reaction conditions for the preparation of the composite adsorbent were optimized.By adjusting the particle size of the magnetic core particles,the thickness of the silica coating,and the surface modification of the composite adsorbent,the composite adsorbent prepared using laterite nickel ore as a raw material was examined for Acid radical adsorption efficiency.Finally,a kinetic model is used for thermodynamic and kinetic analysis to determine the kinetic model and adsorption mechanism of the adsorption process.The research shows that the composite adsorbent prepared from the laterite nickel ore has good adsorption capacity.The equilibrium adsorption amount of the obtained magnetic adsorbent is affected by the preparation conditions.After surfactant modification,the equilibrium adsorption amount is increased.The adsorption process complies with Freundlich model and quasi-second-order kinetic model.The adsorption process proceeds spontaneously and is an endothermic reaction.