The iron-containing electric-furnace steelmaking waste: physical and chemical properties and acidic modification

The electric furnace steelmaking dust is formed at melting metalized pellets in electric-arc steel-making furnaces and is a largetonnage waste. It contains such elements as Fe, Mg, Al, C, Si, Zn, Mn, Na. The ferrous and ferric iron compounds in the EFS dust are mostly presented with oxides — the compounds, which are poorly soluble in aqueous media and can’t take part in exchange reactions under ordinary conditions. The acid treatment with HCl allows obtaining a coagulating suspension, which can be usedfor wastewater treatment. Besides, there was detected up to 14 % of CaO, both free and in calcium silicates such as CaSiO3 and Ca2SiO4. So, in the process of treatment with EFS dust the formation of polysilicic acids helps increasing the purification efficiency.

Optimization of Wastewater Treatment from Cd2+ Ions Using Slag of Electric Furnace Steelmaking Production

The process of purification of Cd2+ ions from model wastewater by the slag of electric furnace steelmaking process was investigated; the kinetic regularities of the sorption process were studied. During the work on the basis of experimental data taking into account the mass of the additive, the temperature of the reaction mixture, the duration of the contact, a mathematical simulation of the reagent-sorption purification process was carried out. Titrimetric, spectrophotometric, atomic absorption methods of investigation were used in the work, chemical composition of slag was established. The article may be of interest to specialists in the field of obtaining new adsorbents using waste products.

CLEANING UP EMERGENCY OIL SPILLS FROM THE WATER SURFACE WITH MAGNETIC ADSORBENTS

There was suggested a method of obtaining a complex adsorbent with magnetic properties for the oil spill clean-up from the water surface by means of controlled magnetic field. As magnetic filler a finely-dispersed iron-ore concentrate in the form of magnetite, obtained by wet magnetic separation of crushed iron ore, was suggested. As an adsorbing component the disintegrating electric-furnace steelmaking slag, obtained by dry air-cooling method, was selected. The mass ratio of components slag:magnetite is 1(1,5÷2,0). For cleaning up emergency oil spills with the suggested magnetic adsorbent a facility, which is installed on a twin-hulled oil recovery vessel, was designed. The vessel contains a rectangular case between the vessel hulls with inlet and outlet for the treated water, the bottom of which is a permanently moving belt. Above the belt, at the end point of it there is an oil-gathering drum with magnetic system. The adsorbent is poured to oil-products layer from a hopper, provided with drum feeder. Due to the increased bulk weight the adsorbent sinks rapidly into the oil layer on the water surface. If the large non-floating flocculi are formed, they sink and sedimentate on the moving belt and are moved to the oil-gathering drum. The saturated adsorbent is removed from the drum surface with a scraper, connected with a gutter, with contains a rotating auger.

CLEANING UP EMERGENCY OIL SPILLS FROM THE WATER SURFACE WITH MAGNETIC ADSORBENTS

There was suggested a method of obtaining a complex adsorbent with magnetic properties for the oil spill clean-up from the water surface by means of controlled magnetic field. As magnetic filler a finely-dispersed iron-ore concentrate in the form of magnetite, obtained by wet magnetic separation of crushed iron ore, was suggested. As an adsorbing component the disintegrating electric-furnace steelmaking slag, obtained by dry air-cooling method, was selected. The mass ratio of components slag:magnetite is 1(1,5÷2,0). For cleaning up emergency oil spills with the suggested magnetic adsorbent a facility, which is installed on a twin-hulled oil recovery vessel, was designed. The vessel contains a rectangular case between the vessel hulls with inlet and outlet for the treated water, the bottom of which is a permanently moving belt. Above the belt, at the end point of it there is an oil-gathering drum with magnetic system. The adsorbent is poured to oil-products layer from a hopper, provided with drum feeder. Due to the increased bulk weight the adsorbent sinks rapidly into the oil layer on the water surface. If the large non-floating flocculi are formed, they sink and sedimentate on the moving belt and are moved to the oil-gathering drum. The saturated adsorbent is removed from the drum surface with a scraper, connected with a gutter, with contains a rotating auger.

Kinematics analysis and experimental investigation of an inclined feeder with horizontal vibration

This paper presents a novel design of an inclined feeder with a chute that vibrates like a simple pendulum. It is designed with a horizontal vibration and an inclined chute for feeding steel scraps in electric furnace steelmaking. The simplified model of the feeder and the governing equations of kinematics analysis are introduced. Numerical integration programs were developed to investigate the kinematics characteristics of the feeder. The inclination angle of the chute and the vibration frequency, two vital impact factors affecting the motion of the fed block, were analyzed. Compared with the traditional horizontal chute feeder, this novel feeder has proved to be more efficient and speed-controllable. An experimental prototype was fabricated and feeding tests were performed. Results indicate that good agreement between calculation and experiment was achieved on the motion of the fed block. A stepped chute was proposed to solve the problem of block intertwining and uneven dropping during the feeding. The simulation of the multi-block feeding showed that the feeding with the stepped chute was steadier than that with the smooth chute. This research indicates that the mathematical model is able to predict the motions of the system and the new feeder will be capable and effective in performing the steel scrap feeding task.