• Korean Journal of Materials Research
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• v.16 no.5
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• pp.336-340
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• 2006

Fluorspar has been essential flux in steelmaking process. The main effects of fluorspar addition are lowering of the viscosity and melting temperature of slag. In recent years, due to the increasing price and environmental problem of fluorspar, various types of fluorspar substitute have been investigated. In this study, iron oxide by-products such as sinter dust, basic oxygen furnace (BOF) sludge and mill scale were developed as a substitute in terms of waste recycling. Several plant trials were carried out by addition of briquetted substitutes of $4{\sim}6$ kg/ton to compare with the fluorspar of $0.7{\sim}1$ kg/ton. The substitutes showed a similar behavior of slag formation, phosphorus removal and MgO saturation content.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.3
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• pp.205-211
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• 2000

This study was conducted to evaluate the residual effects of basic oxygen furnace (BOF) slag applied in rice paddy fields as soil conditioner one year before. The experimental fields of Lim et al. (2000) located in Youjung and Nampyung were used for this purpose. Both variety (Oryza sativa L. cv. Dongjinbyeo) and cultural practices were the same as those in Lim et al. (2000). Soil chemical properties, plant height, number of tillers per plant, yield and yield components were observed. The temporal variation of treatment mean value in soil chemical properties appeared to be similar trends in both Youjung and Nampyung experimental fields. Soil pH and Ca content were still significantly higher than those in control treatment up to July of the second season, but decreased progressively as time passed. However, the effects lasted longer as slag rate became higher. BOF slag seems to have residual effects as a soil conditioner or Ca fertilizer in soil for two years. BOF slag rate of $4Mg\;ha^{-1}$ raised soil pH almost the same as lime rate of $2Mg\;ha^{-1}$. Content of $SiO_2$ in soil applied slag appeared to be higher compared with control. Fe and Mg content in soil with slag treatment was significantly higher than that of control in 1997, but it was almost the same level as that of control in 1998. In YouJung experimental field, rough rice yield of slag teatment became higher as slage rate incresed. Slag rate of $12Mg\;ha^{-1}$ showed the highest rough rice yield of $5,400kg\;ha^{-1}$ among treatment, which was 14% higher than that of control with $4,720kg\;ha^{-1}$. Slag rate of $12Mg\;ha^{-1}$ showed relatively higher plant height and higher number of tillers at the early growth stage compared with other treatments. In NamPyung experimental field, rough rice yield was the highest at the plot of lime rate $2Mg\;ha^{-1}$ and became higher as slag rate increased. There were no significant differences in rough rice yield between lime treatment and slag treatments. Slag rate of $12Mg\;ha^{-1}$ showed the highest rough rice yield of $7,170kg\;ha^{-1}$ among slag treatment, which was 8% significantly higher than that of control with $6,670kg\;ha^{-1}$. Slag rate of $12Mg\;ha^{-1}$ showed relatively slower growth in plant height at the early growth stage, but superior growth at the later growth stage, and significantly higher number of spiklets per panicle and 1000-grain weight than that of control.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.631-638
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• 2010

The objective of this study was to evaluate the efficiency of zerovalent iron and basic oxygen furnace slag on arsenic stabilization in soils. For this, arsenic (V) contaminated soil and roxarsone contaminated soil were incubated after incorporation with zerovalent iron (ZVI) or basic oxygen furnace slage (BOFS) at four different levels (0%, 1%, 3%, and 5%) for 30 days and then the residual concentrations of arsenic were analysed following extraction with aqua reqia, 1N HCl and 0.01 M $CaCl_2$. The total concentration of arsenic was 2,285 mg/kg in the As(V) contaminated soil and 6.5 mg/kg in the roxarsone contaminated soil. 1 N HCl extractable arsenic concentration in the As(V) contaminated soil was initially 1,351 mg/kg and this was significantly declined by 713~1,034 mg/kg following incubation with ZVI while BOFS treatment showed no effect on the stabilization of inorganic arsenate except 5% treatment which showed around 100 mg/kg reduction in 1N HCl extractable arsenic. Similarly, in the roxarsone contaminated soil 1N HCl extractable concentration of arsenic was reduced from 3.13 mg/kg to 0.69 mg/kg with ZVI treatment increased from 1% to 5% while BOFS treatment did not lead to any statistically significant reduction. Available (0.01M $CaCl_2$ extractable) arsenic was initially 0.85 mg/kg in the As(V) contaminated soil and this declined by 0.79 mg/kg following incorporation with 5% ZVI, which accounted for more than 90% of the available As in the control. When As(V)-contaminated soil was treated with BOFS, the available arsenic was increased due to competing effect of the phosphate originated from BOFS with arsenate for the adsorption sites. For the roxarsone contaminated soil, the greater the treatment of ZVI or BOFS, the lower the available arsenic concentration although it was still higher than that of the control.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.699-706
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• 2001

This study was conducted to evaluate the effectiveness of basic oxygen furnace (BOF) slag as soil conditioner in a nursery and two natural forests. The BOF slag was applied at rates of 0, 4, 8, and 12 t/ha for seedbed nursery of three tree species-Pinus densiflora, Larix leptolepis and Amorpha fruticosa; and 0, 10, 20, and 40 t/ha for Pinus densiflora natural forests located at two sites. In case of the nursery study, the significant increase in soil pH and contents of Ca, Mg, $SiO_2$, Fe and Mn was noticed after six months of the BOF slag application. Dry weight of Pinus densiflora seedlings with BOF slag treatments was lower compared with that of control. There were no significant differences among treatments in dry weight of Larix leptolepis seedlings. Dry weight of Amorpha fruticosa seedlings, which are deciduous species and grow rapidly at seedling stage, increased significantly and T/R ratio decreased as BOF slag rate increased. The differences of effects of BOF slag application on the seedlings of tree species may be attributed to the differences of optimum pH range of the species. In Pinus densiflora natural forests, there were no significant differences in soil pH and contents of $SiO_2$, Fe and Mn among the treatments, but these values became higher as BOF slag rate increased. Contents of Ca in soil became significantly higher as BOF slag rate increased. There were no significant differences among treatments in net production of mature Pinus densiflora trees, but BOF slag rate of 10ton/ha showed the highest net production. Young Pinus densiflora trees at the plots of BOF slag rate of 10 t/ha showed significantly higher root collar diameter growth rate and twig net production than those of other treatments. It may be given as a conclusion that BOF slag application in nursery and forest soil increased soil pH and contents of Ca, $SiO_2$, Fe and Mn in soil and they showed the ability of BOF slag to be used as a soil conditioner in strongly acid soil.