Study On The Performance Of Steel Slag To Prepare Permeable Brick Or Adsorption Of Heavy Metal Ions

Steel slag is the industrial solid waste produced in steelmaking process.How to make full use of steel slag resources is of great significance to promote the sustainable development of iron and steel enterprises.The application of steel slag in the preparation of steel slag permeable brick and the adsorption of heavy metal ions in waste water is an effective way to recycle steel slag.Based on steel slag as raw materials,this paper studies the physical and chemical properties after its original state and modification,and use of the preparation of the high strength and high permeable coefficient of steel slag permeable brick,particle size of the system of dosage of steel slag,steel slag,bone glue ratio,molding process and the molding pressure of permeable brick permeable coefficient and the influence law of compressive strength,analyzes the different influence of the main reasons.The adsorption capacity of steel slag for heavy metal Cu²⁺and Hg²⁺ions was studied.The effects of slag addition amount,adsorption time,initial concentration of Cu²⁺and Hg²⁺ions and reaction temperature on adsorption properties were investigated.And it carries on the kinetic and isothermal adsorption model analysis,obtains the suitable fitting model equation through the analysis calculation,analyzes its adsorption mechanism.Steel slag was modified by high temperature and additives,and used to adsorb heavy metal Cr⁶⁺ions.The influence of various factors on the adsorption effect of Cr⁶⁺ions was investigated.The research results are as follows:（1）The effect of steel slag content,steel slag particle size,bone glue ratio,forming pressure and apparent porosity on permeability coefficient and compressive strength of permeable brick were studied,and the relationship between permeability coefficient and compressive strength of permeable brick was analyzed.The results show that the steel slag content,bone glue ratio and steel slag particle size have significant effects on the compressive strength and water permeability of steel slag permeable brick.When the diameter of steel slag is 3～5 mm,the permeability coefficient and compressive strength of permeable brick are 4.4×10^-2cm/s and 51.66MPa,respectively.It is found that the mechanical properties and water permeability of the permeable brick made by vibration forming are better than those made by static pressing forming.（2）The apparent porosity directly affects the water permeability coefficient.High apparent porosity contains more holes and is more conducive to the passage of water flow.However,high apparent porosity will lead to the decrease of compressive and flexural strength.There is a negative linear correlation between water permeability coefficient and compressive strength of steel slag permeable brick.（3）Experimental study on the adsorption of Cu²⁺and Hg²⁺by steel slag,it is concluded that steel slag can well adsorb Cu²⁺and Hg²⁺in wastewater,and the removal rate can reach more than 90%.The adsorption kinetics analysis shows that the adsorption process of Cu²⁺and Hg²⁺by steel slag accords with pseudo first-order kinetics equation,indicating that the adsorption rate of Cu²⁺and Hg²⁺by steel slag is greatly affected by diffusion.The adsorption of Cu²⁺by steel slag is highly fitted to The Freundlich adsorption isotherm equation,while the adsorption of Hg²⁺by steel slag is more consistent with the Langmuir adsorption isotherm equation,indicating that the adsorption processes of the two ions are different.Cu²⁺belongs to complex surface adsorption,while Hg²⁺belongs to monolayer adsorption.（4）Steel slag was modified by high temperature and additives.After modification,the pore size of desulfurization slag became larger,and the adsorption material with larger porosity had stronger adsorption capacity.It was used to adsorb heavy metal Cr⁶⁺ions,and the influence of various factors on the adsorption effect of Cr⁶⁺ions was explored.The results show that the modified steel slag has a good adsorption effect on Cr⁶⁺wastewater,and the adsorption rate can reach 85%.