• Journal of Conservation Science
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• v.36 no.4
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• pp.275-283
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• 2020

Iron oxides are the essential coloring oxides in traditional ceramic glazes. However, when Fe is involved in the coloration in the form of ions or colloids in glazes with low Fe content, it is difficult to identify the iron oxide phases. Generally, in many these glazes, Ca-rich minerals are observed by X-ray diffraction (XRD) or microscopic images, owing to their devitrification by the high Ca content. This study attempts to elucidate the correlation between the crystalline structure and coloration in the glazes while mainly focusing on neoformed Ca-rich minerals and Fe content. An experimental firing was carried out to produce tree ash glazes, with pine tree ash and Buyeo feldspar. In the case of oxidation glazes, the scanning electron microscopy (SEM) images and XRD patterns did not exhibit any Ca-rich crystals, and all the visible light reflectance spectra lines exhibited a similar shape. In contrast, the reduction glazes divided into blue glazes and other colored glazes according to the shapes of their reflectance spectra. It was confirmed that the influence of Ca-rich minerals on the glaze color was more pronounced than the blue color of the reduction glazes when the Ca and feldspar contents were sufficiently high and low, respectively, to form wollastonite. As the Ca content increased and the elemental composition of the reduction glazes changed, the neoformation of the Ca-rich minerals, such as wollastonite, anorthite, diopside, and akermanite was sequentially observed.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.1
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• pp.25-30
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• 1978

Field experiments were conducted on the cropping system soybean-barley-soybean to investigate the effect of phosphorus and wollastonite application, effective application methods of phosphrus, and their residual effect in a typical Jeju island volcanic ash soil when the fertilizers were applied to the first crop of the three crops sequence. The results are summarized as follows. 1. Response of phosphorus was higher for barley than for soybean. The maximum application rate of phosphate was extimated to be 10-20kg/l0a for cultivation of soybean first crop) and 100kg/l0a for barley (second crop). Barley yield under 100kg/l0a of phosphate was double as compared to the no phosphate plot. 2. With application of 100kg/10a phosphate at the sowing time of soybean, the available phosphate in the soil after harvesting of soybean was increased to 175ppm but decreased to 60 ppm by cultivation of barley (second crop.) On the other hand, the phosphate absorption coefficient was 1,146mg/100g after soybean harvest but increased to 1,764mg/100g after barley harvest. 3. High residual effect was found in the plot to which phosphate applied with compost in the sowing band. 4. Response to wollastonite under heavy application of phosphate was high and residual effect was also great. 5. Response of soybean to wollastonite was higher than that of barley. Application of wollastonite increased the yield of all three crops soybean (first crop) by 30%, barley (second crop) by 12% and soybean (third) by 20%, respectively. Highest yield was obtained from the 1,000kg/10a wollastonite treatment for soybean and 500kg/l0a for barley.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.3
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• pp.163-168
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• 1981

The studies were carried out to examine the effect of soil improvement agents, such as lime, wollastonite and phosphate, in reducing the damage caused by hydrogen fluoride gas to the vegetative growth of rice. The yield loss, damage rate of the plant leaves, the fluoride and silicate concentrations of the plants were measured. The results obtained are summarized as follows : 1. Of various levels of added lime and wollastonite, the best were found to be neutralized lime plus lime 150kg/10a, and wollastonite 150kg/10a. 2. Added fluoride increased the fluoride content of the plant and the damage rate of the plant leaves, and the yield was greatly decreased. 3. The silicate concentration at harvesting period was also increased by high amounts of fluoride in the plant during vegetative growth. 4. Increasing the amount of added lime increased the watersoluble silicate concentration in the soil. The silicate content of the plant showed the same tendency.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.3
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• pp.155-161
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• 1974

In order to investigate the effect of split application of silicate fertilizers on the rice plant, this studies, designed with two kinds of silicate material, wollastonite and high concentrated fused silicate material, and 4 types of application dates on the pot experiment without chemical control against diseases, have conducted the silica analysis of rice plant and diseased rates of plant during the all growing stages. The silica contents in rice plant with basal application were increased most highly compared with the split applications during the all growing stage, but they were all much the same between the basal and split application at the harvest. High concentrated fused silicate material was more useful to increase the silica content in rice plant than wollastonite and effect of split application of silica was dominant with this fused silicate material. The diseased leaf area by rice blast was decreased from the 50% of uncontrolled plot to 20~40% by the split application with wollastonite and to 5~15% with high concentrated fused silicate material. Also percents of deseased panicles were decreased to 20% with wollastonite and to 10% with high concentrated fused silicate material.

• Economic and Environmental Geology
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• v.11 no.4
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• pp.143-167
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• 1978

The Sangdong tungsten (mostly scheelite) mine is located on the southern limb of a major syncline, the Hambaeg syncline, in a thick sequence of lower Paleozoic sedimentary rocks in the mideastern part of south Korea. Productive scheelite mineralization in Sangdong area is confined to one single formation, the Myobong Slate. Four major ore beds, which have an lateral extension over than 1 km and were not heavily subjected to spatial disturbance, are developed in the Myobong Formation. The original materials of the ore-comprising horizones were probably of either calcareous or silceous sediments. The four ore beds, especially in the case of Main ore bed, display both lateral and vertical zoning. Association quartz-mica-scheelite is predominant in the central, while association hornblende-quartz-diopside-scheelite, diopside-garnet and wollastonite-garnet are developed in this order towards the periphery of the ore beds. Petrologically, two phases of thermometamorphism are recognized. The first phase is represented by the association wollastonite-garnet and diopside-garnet, while the second phase by the association hornblende-quartz-diopside-scheelite and quartz-mica-scheelite. The associations of the second phase do constitute prodctive ore. The high background value of tungsten in the area surrounding the Sangdong mine reveals that the area can be considered a geochemical zone enriched in tungsten. Studies on the trace element patterns were carried out to draw useful criteria for the purpose of future geochemical exploration in the area. The increasing trend of the ratio Rb $({\times}1000)/K_2O$ of the Myobong Slate towards the known mineralization area proved to be indicative for the presence of tungsten mineralization.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.2
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• pp.83-89
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• 1979

To improve the physico-chemical properties of sandy alluvial soils for paddy rice, several soil amendments such as wollastonite, dolomite adding red earth and compost were applied compositely. The results are summarized as follows. 1. The application of soil amendments caused an increase of calcium, magnesium and silica contents in the soils, and it was also possible to maintain a high pH during the cropping season. 2. Among the mineral elements in the plant, calcium and silica content were increased by the treatment of adding red earth, dolomite and wollastonite. 3. By the application of wallastonite and dolomite, the phosphorous content in the plant decreased in comparison with no-amendment treatment, and the potash in the plant also decreased after the ear formation stage of the rice. 4. The most desirable treatment (adding red earth+dolomite+extra N) resulted in 19% increase of rice yield, while the composite of wollastonite and compost brought 10% yield increase. The high ripeding ratio was the factor which influenced the yield favorably.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.321-325
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• 1986

A laboratory experiment was conducted to investigate silica solubility in soil with specific reference to the characteristics of iron refinery slag and wollastonite. The results are as follows; 1. The slilia concentrations successively extracted by distilled water and N-NaOAc (pH 4.0) in soil treated with the two silicate fertilizers, is higher in iron refinery slag than in wollastonite, while the pH values of soil-fertilizer suspensions successively extracted by distilled water were the opposite. 2. Silica concentrations due to increasing of fertilizer application were decreased in iron refinery slag-soil suspensions but the concentrations were increased in wollastonite-soil suspensions. 3. The amounts of silica adsorbed in different pH of soil suspension were maximized under the condition maintained pH of near to 9.4.

• Journal of Conservation Science
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• v.25 no.4
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• pp.439-450
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• 2009

The purpose of this study is to find out characteristics of the fillers made by epoxy resin (L-30) and filling epoxy resin (L-50) with talc, quartz sand and wollastonite with different mixture ratio of 5%, 50%, 80%, 120%, and 150%. The viscometer and colorimeter were used to measure the viscosity and chromaticity of the fillers. Additionally, IC and SEM were used to reveal characteristics of the filler, and checked ultrasonic wave velocity, compressive strength and contact angle to estimate the stability between the filler and stones which are essential for conservation treatments. The filler mixed with the talc had the lowest value in the ultrasonic wave velocity analysis, and its compressive strength decreased as the mixing rate of talc increased. On the other hand, wollastonite had higher values than others in the ultrasonic wave velocity and the compressive strength regardless of epoxy resin type, also, these values increased as mixing rate increased. The properties of the filler, which include the granularity and shape, have influence on characteristics of the stone conservation adhesives. Thus, the filler type, characteristic, and mixture ratio must be considered for effective conservation treatment.

• Korean Journal of Environmental Agriculture
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• v.4 no.2
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• pp.102-107
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• 1985

A pot experiment was conducted to find out the effects of water management, slaked lime and wollastonite on growth and Cu uptake of rice at Cu added soil. The soil was adjusted to 0, 50, 100 and 200 ppm concentration of Cu. The application amount of slaked lime was the lime requirement plus 150 ㎏/l0a and wollastonite 200 ㎏/10a, respectively. The copper concentration in soil which reduced yield significantly was 133.1 ppm for submersion and 136.8 ppm for intermittent irrigation. The application of lime and wollastonite reduced Cu content in brown rice as well as increased rice yields compared to that of no lime. The copper content in plant was increased with increasing soil Cu concentration, however, reduced with submersion and application of slaked lime, and increased with increasing the ratio of Cu/Ca+Mg equivalent in soil.

• Journal of the Korean Ceramic Society
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• v.39 no.5
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• pp.490-497
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• 2002

Sintering property, mechanical property and bioactivity of $CaO-SiO_2-B_2O_3$ glass-ceramics were investigated. This glass-ceramics was sintered at 750-830${\circ}$ and showed nearly pore-free microstructure. The glass-ceramics consisted of three phases, i.e. monclinic-wollastonite, calcium borate and borosilicate glass matrix. The mechanical strength was higher than that of other bioactive ceramics, especially compressive strength(2813 MPa) and fracture toughness($3.12 MPa{\cdot}m^{1/2}$). Bioactivity of the glass-ceramics depends on amount of $CaB_2O_4$ and borosilicate glass matrix. It might be likely that more soluble $CaB_2O_4$ raises supersaturation of Ca ion in SBF solution and borosilicate glass forms Si-OH group that presents nucleation site of hydroxycarbonate apatite(HCA) layer. So, glassceramics of more $CaB_2O_4$ and borosilicate glass showed better bioactivity.