Corrosion of Magnesia-chrome Brick by Smelting Reduction Slag with Iron Bath

Effects of FeO content （0, 5%, 10%, and 15% in mass, respectively ） in lab-synthesized smelting redttc- tion slag with iron bath and test temperature （1 450, 1 500, 1550, anti 1 600 ℃ ） on corrosion am,amount and microstructure of fused rebonded magnesia - chrome brick with 26.02 massqc of Cr2O3 were researched by rotary cylinder method. The results show that ： （ 1 ） the corro- sion amolult of magnesia -chrome brick by slag without FeO is higher than that by the slag with 5% FeO, and the vorrosion amount increases when FeO content increa- ses from 5% to 15% ; （2） the test temperature is one of the important factors affecting the slag corrosion resist- ance of magnesia - chrome brick, and the corrosion of smelting reduction slag to brick increases with the temperature rising.

Washing out heavy metals from contaminated soils from an iron and steel smelting site

Washing is a promising method for separating contaminants bound to the particles of soil ex-situ by chemical mobilization. Laboratory batch washing experi- ments were conducted using deionized water and varying concentrations of oxalic acid, citric acid, tartaric acid, acetic acid, hydrochloric acid and ethylenediaminetetra acetic acid （EDTA） to assess the efficiency of using these chemicals as washing agents and to clean up heavy metals from two heavily polluted soils from an iron and streel smelting site. The toxicity reduction index and remediation costs were analyzed, and the results showed that the soils were polluted with Cd, Pb and Zn. Hydrochloric acid and EDTA were more efficient than the other washing agents in the remediation of the test soils. The maximum total toxicity reduction index showed that 0.5 mol·L^-1 hydro- chloric acid could achieve the remediation with the lowest costs.

Numerical simulation of flow characteristics of side-bottom combined blowing in iron bath reactor

A numerical model of an iron bath smelting reduction furnace with side-bottom combined blowing was established to study the influence of blowing arrangements on the stirring effect of the molten pool,and the accuracy of numerical simulation was verified by water model experiment.By comparing the flow field of molten pool with single nozzle,double nozzles(symmetrical and asymmetrical),and four nozzles(symmetrical and asymmetrical),the proportion of dead zone,average turbulent kinetic energy,and mixing time,the results show that asymmetrical bottom blowing is better than symmetrical bottom blowing,and the effect of double nozzles bottom blowing was better than that of four nozzles bottom blowing.The mixing effect is the worst under the condition of single nozzle.When the bottom blowing is asymmetrical with double nozzles,the mixing time is the shortest.Under the condition of double nozzles asymmetrical bottom blowing,when the insertion angle and depth of side lance are larger and deeper,the velocity streamline of molten slag layer is denser and the value is larger;meanwhile,the reflux of molten iron layer is larger,the proportion of dead zone is smaller,and the whole molten pool is fully stirred.When the insertion depth of the side lance is deeper,the gas holdup in the molten pool is greater and the stirring of the molten pool is more intense,while the insertion angle has little effect on the gas holdup.By comparing the influence of different side blowing conditions on the slag layer,it is found that the slag layer is divided into two layers by double-layer side lance,with the critical surface of the slag layer at about 200-260 mm from the bottom,and the insertion depth of the lower side lance has a greater influence on the layering of the slag.

Evolution of the“ancient Kedah”:A study on urban forms at Sungai Batu Archaeological Complex(SBAC),Bujang Valley,Kedah,Malaysia

Archaeological research at the Sungai Batu Archaeological Complex(SBAC),which has been carried out until 2023,aims to complete the chronological data and urbanization process of the ancient Kedah.This study will especially prove that the ongoing urbanization process is aimed at developing the iron smelting industry and trade in ancient Kedah,especially in SBAC.This is because archaeological research at SBAC has proven that with the existence of the ancient Kedah iron smelting workshop at SBAC,river jetties,port management,rituals,and Buddhist monuments began to be erected,all of which can be determined by chronometric dating.The results of the chronometric dating have proven that the ancient Kedah Kingdom existed since the 6th century BC and was oriented towards the trade of iron resources,which allowed the use of the area to grow rapidly.The process of urbanization and land use clearly conforms to Lynch’s principle,which emphasizes the principles of 1)paths,2)edges,3)districts,4)nodes,and 5)landmarks in the development process of land use and urbanization in the complex.