Graded Utilization Of Arc Furnace Nickel Iron Slag-Used As Machine-Made Sand For Preparation Of Concrete And Ceramic Tile Adhesive

Stainless steel smelting enterprises in Yangjiang City,Guangdong Province use the RKEF method of nickel-iron and stainless steel integrated smelting process,which will produce different nickel slag,and the accumulation of nickel slag has caused huge environmental pressure on the local area.Among them,the largest output is arc furnace nickel-iron slag,and preliminary studies have shown that it has the potential to be prepared as machine-made sand.Combining with the current situation of the shortage of construction sand in Guangdong Province,this paper conducts research on the preparation of manufactured sand from arc furnace nickel iron slag.In order to improve the utilization efficiency and economic benefits,arc furnace nickel iron slag is prepared as machine-made sand for concrete and ceramic tile adhesives.Firstly,this article studied the chemical composition and mineral composition of arc furnace nickel-iron slag to clarify its potential hazards.The results show that the main chemical components of arc furnace nickel-iron slag are SiO₂ and MgO,as well as a small amount of Al₂O₃ and CaO.The main mineral is forsterite.The safety research of arc furnace nickel iron slag has shown that its radioactivity and toxicity leaching inspection is qualified,stability and alkali aggregate reactivity are qualified,and it will not have adverse effects on environmental safety and structural safety,and meet the requirements of building materials.basic requirements.However,the arc furnace nickel-iron slag has relatively coarse particles and poor sphericity,and needs to be crushed to prepare the cement and ceramic tile adhesive machine-made sand.The machine-made sand for both uses has the problem of poor gradation.The porosity is reduced from 42%to 39%after the Fuller gradation of concrete sand is optimized,and the sand for ceramic tile adhesive is optimized by Dinger＿Funk close-packed model.The back void ratio is reduced from 48%to 42%.Then,this paper conducts research on the preparation of arc furnace nickel-iron slag machine-made sand into concrete.It is found that the arc furnace nickel-iron slag machine-made sand concrete without grading optimization will show the phenomenon of excessive slump loss over time.After analyzing the possible factors,this article proposes three solutions to solve this problem.include:（1）Use high-efficiency polycarboxylic acid water reducer with retarding function components;（2）When using ordinary water-reducing agent,add water-reducing agent by post-mixing method;（3）According to the Fuller gradation curve,the gradation optimization is carried out in the production process of submerged arc furnace nickel iron slag machine-made sand.After solving the problem of slump loss over time of the arc furnace nickel iron slag machine-made sand concrete,according to the ordinary concrete mix design method,the river sand concrete,sandstone machine-made sand concrete,and arc furnace nickel iron slag machine-made sand concrete were designed with the same strength grade of C35.The results show that the 28-day compressive strength of arc furnace nickel-iron slag machine-made sand concrete is 53.6MPa,which is 4MPa and 3MPa higher than river sand concrete and sandstone machine-made sand concrete by mixing concrete with C35 strength grade and the same slump;The electric flux and chloride ion migration coefficient of the hot furnace nickel iron slag machine-made sand concrete are the smallest,and the chloride ion penetration resistance is better.This is due to the rough surface of the machine-made sand with optimized gradation,the more angular particle characteristics and the certain pozzolanic activity,which makes the bonding between it and the cement paste better and the structure more compact.Next,this article studied the preparation of ceramic tile adhesives from arc furnace nickel-iron slag machine-made sand.The results show that the use of arc furnace nickel-iron slag machine-made sand can be formulated to meet the tensile requirements of"Ceramic Tile Adhesive"（JC/T547-2017）The C1T anti-slip ordinary cement-based adhesive with a bonding strength greater than 0.5MPa and the C2T anti-slip reinforced cement-based adhesive with1.0MPa.When reaching the same consistency of 70-80mm,the water consumption of the arc furnace nickel iron slag machine-made sand ceramic tile adhesive after grading optimization is3-12kg/m3 less than before optimization,and the tensile bonding strength is better than before optimization.Increase by 30%～80%.Finally,referring to the building mortar mix design method in the standard"Masonry mortar mix design specification"（JGJ/T 98-2010）,the mix ratio of the arc furnace nickel iron slag machine-made sand ceramic tile adhesive before and after grading optimization is proposed.Design method.And mixed with nickel slag mineral admixture and arc furnace nickel iron slag machine-made sand to prepare ceramic tile adhesive.Compared with the C2TE adhesive prepared by a certain brand company,it can not only reduce the amount of cement and functional additives,but also has better performance..Compared with the C2TE adhesive formulated by a certain brand company,the raw material cost is 54%lower.This study expands the application range of submerged arc furnace nickel-iron slag and improves the utilization value and economic benefits of the harmless treatment of arc furnace nickel-iron slag.This will protect the local environment of Yangjiang City and maintain the sustainability of the ferronickel smelting industry in Yangjiang Development is of great significance.