• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.537-541
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• 2001

For the development of reformation material of soft ground using the LD slag, the relation to the particle condition of LD slag and the pH behavior of slag dissolution water, extraction properties of slag, and origination of white water were investigated. When the LD slag is mixed with sea water, the pH of solution ranged between 9.47 and 10.0. On the other hand, when mixed with distilled water, the pH was about 10.4 to 12.1. For the as-received slag and the aged slag in sea water, a pH of 11.5 to 12.0 was observed when the particle size was less than 0.5mm. For the reoxidized slag in seawater, the pH of the solution was lower than 9.5 when the particle size was bigger than 0.075mm. For the aged slag and reoxidized slag, the pH of the solution remained constant when the addition ratio of sea water to the slag was higher than 500 times. The main elements dissolved from the slag were Ca and Mg ions. When the pH went over 9.0, the white water started to font which was caused by the CaCO$_3$and Mg(OH)$_2$.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.526-531
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• 2001

LD slag, that is, a by-product of steel making process, has been mainly used as land construction materials. Recently, the seashore application of LD slag was tried in Japan and Korea tut the reaction between LD slag and seawater was not studied yet. We tried to clarify the leaching reaction and/or mechanism of LD slag and the reaction between seawater and LD slag. We tried to apply these results to the decarbonization of seawater for seawater magnesia process. At first, LD slag was milled and classified into 5 grades, that is, (ⅰ)45${\mu}{\textrm}{m}$ under, (ⅱ)0.25~0.5mm (ⅲ)0.5~1mm(ⅳ)1~2mm, (ⅴ)2.36~3.35mm. These slags were leached in the distilled water. In case of 45${\mu}{\textrm}{m}$ under, the pH of the leached solution was over 12. The chemical analysis of leached solution showed that the $Ca^{+}$$^2$was main component and the S $i^{+}$$^4$was very low. On the other hand, the content of S $i^{+}$$^4$in leached solution was decreased with the increase of pH of this solution. The nearly pure calcium solution was made and the ultra high purity MgO could be made with this calcium solution. The leaching behavior of LD slag was different between the fine particle and coarse particle. The calcium was leached by bulk dissolution in the coarse particle and by surface controlled reaction in fine particle. The leaching rate was slow in coarse particle and fast in fine particle. Therefore, the high pH solution, that is, over 12, was obtained in fine particle.cle.e.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.532-536
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• 2001

LD slag, that is, a by-product of steel making process, has been mainly used as land construction materials. Recently, the seashore application of LD slag was tried in Japan and Korea but the reaction between LD slag and seawater was not studied yet. We tried to clarify the leaching reaction and/or mechanism of LD slag and the reaction between seawater and LD slag. We tried to apply these results to the decarbonization of seawater for seawater magnesia process. The high pH solution(over 12) was injected into the sea water and the pH of mixed liquid was adjusted to 9.8. This mixed solution was aged for 8 hours and the 104ppm of CO$_3$$^{-2}$ in the sea water was decreased to 23ppm with the negligible loss of $Mg^2$$^{+}$. The slag particle was directly inserted into the seawater fur practical application. The 0.5~1mm particles were suitable for decarbonization when 5 grade slags mentioned above were reacted with sea water. In this case, the content of CO$_3$$^{-2}$ in the sea water was 53 ppm with the negligible loss of $Mg^2$$^{+}$ after 8 hours aging. The direct application of slag particle fur the decarbonization of seawater takes more reaction time.ime.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.503-507
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• 2001

In this paper the forming and the unique properties of PZH blast furnace slag, bearing TiO$_2$ 22~25%, have been introduced. The utilization of this kind of blast furnace slag, especially about recycling resource of TiO$_2$included in it, has been reviewed and discussed. According to research work experiences and tendency of new materials developing some suggestions about future research on PZH blast furnace slag have been put forward.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.379-382
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• 2000

In this paper, we evaluated the suitability of converter slag as concrete aggregate by measuring physical and chemical characteristics of converter slag. The converter slag mainly contains SiO₂and CaO as the chemical composition. The reaction with water and a little of free CaO in the slag causes slag's volume to expanse. Therefore, we used several aging method in order to decrease the characteristics of slag volume expansion. Then the compressive strength of concrete with the converter slag aggregate is measured.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.541-546
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• 1998

To study the possibility of agricultural utilization of the sewage sludge and the converter slag, the chemical properties of soil, the growth response of corn plant and uptake of inorganic nutrients in plant tissues were investigated by application of the composts made of the sewage sludge and converter slag. Uptake of inorganic nutrients in stem and leaf of corn plant were decreased by applications of the composts. The content of heavy metals in soil and corn plant were investigated, but the results of show that the concentrations of heavy metals are much low.

• Journal of the Korea Institute of Building Construction
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• v.5 no.1 s.15
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• pp.81-88
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• 2005

As a part of efforts for conformity of demand to high quality of concrete and for solution of economic problem, blast-furnace slag has been utilized by means of cement replacement. With utilization of blast-furnace slag, superior performance can be ensured, environmental pollution can be prevented and economical advantage can be obtained. But blast-furnace slag has a lot of disadvantages like retardation of strength manifestation etc. in field construction, so properties examination of concrete using blast-furnace slag instead of cement is necessary. For upper necessity, it is planed that basic data for utilization and performance management of blast-furnace slag by means of cement replacement is presented with experimental comparison and investigation of engineering properties of concrete according to the replacement ratio and fineness of blast-furnace slag.

• Journal of the Korean Ceramic Society
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• v.15 no.3
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• pp.149-156
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• 1978

The utilization of waste and industrial byproduct materials, such as blast furnace slag, shales, poor coal and anthracite briquet ash, were investigated as a source of calcareous or argillaceous material in the manufacture of Portland cement. As a slag is similar to cement in chemical compoment and contains about 40∼50% of CaO, it's utilization in cement manufacture should be suitable. The burnability was increased and the heat of clinker formation was decreased by using slag. Some consideration should betaken in the use of large quantity because of sticking in suspension preheater kiln. Suitable quantities of colliery shales and poor coal should be useable in cement manufacture as a argillaceous materials and also its combustible materials should be utilized in cement manufacture. Anthracite briquet ash is also usable as a argillaceous source and it gives good burnability.

• Resources Recycling
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• v.13 no.2
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• pp.33-38
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• 2004

Concepts and experimental results for the unique utilization process which we could obtain the high purity calcium nitrate from blast furnace slag in the steel industry are described. Firstly we reacted the blast slag with nitric acid and separatively removed the insoluble silica by filtration. We adjust the pH of filtrate to 6∼8 with calcined lime, and then precipiated out the metal components like Fe, Al, Mg in the forms of hydroxides. Consequently concentration of the mother liquor and crystallization processes make us obtain the high purity (>98 wt%) calcium nitrate tetrahydrates, which is expected the valuable fertilizers.

• Geomechanics and Engineering
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• v.31 no.2
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• pp.149-158
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• 2022

Ladle furnace (LF) slag, waste from the steel-making process, was incorporated to improve the compressive strength of soil cement. LF slag was mixed to replace the cement in the soil-cement samples with wt% ratio 20:0, 15:5, and 10:10 of cement and slag, respectively. LF slag in the range of 5, 10, and 20 wt% was also separately added to the 20-wt% cement-treated soil samples. The soil-cement mixed LF slag samples were incubated in a plastic wrapping for 7, 14, and 28 days. The strength of soil cement was highly developed to be higher than the standard acceptable value (0.6 MPa) after incorporating slag into soil cement. The mixing of LF slag resulted in more hydration products for bonding soil particles, and hence improved the strength of soil cement. With the LF slag mixing either a replacement or additive materials in soil cement, the LF slag to cement ratio is considered to be less than 1, while the cement content should be more than 10 wt%. This is to promote a predominant effect of cement hydration by preventing the partially absorbed water on slag particles and keeping sufficient water content for the cement hydration in soil cement.