• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.342-345
• /
• 2000

Effect of volcanic ash on cell growth of Aspergillus sp. and production of exopolymers by Agrobacterium sp. and Aureobasidium pullualns was investigated. The volcanic ash contained various mineral salts such as $SiO_2$, $Al_2O_3$, CaO, $K_2O$. Maximal cell growth of Aspergillus sp. was obtained when 0.3% volcanic ash was added to medium. Cell growth of Aspergillus sp. increased with higher concentration of volcanic ash in medium. Amount of cell growth with 0.3 % volcanic ash was 6.7 times higher than that without volcanic ash. Volcanic ash also stimulated production of exopolymer as well as cell growth. Production of curdlan with 0.1% volcanic ash was 12.40 g/l whereas that without volcanic ash was 9.15 g/l. Production of pullulan with volcanic ash was also higher than that without volcanic ash.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.55 no.3
• /
• pp.129-140
• /
• 2013

Bottom Ash is industrial by-product from a thermoelectric power plant. An immense quantities of bottom ash have increased each year, but most of them is reclaimed in ash landfill. In this study, in order to raise recycling rate of Bottom Ash, it is suggested to cure Bottom Ash (BA) mixtures mixed with cement, lime, Fly Ash (FA), and oyster shell (OS). Mixtures of 5~20 % mixing ratio had been cured for 1, 3, 7, 14, and 28 days using sealed curing and air-dry curing method. Unconfined compressive strength test was conducted to determine strength and deformation modulus ($E_{50}$) change for mixtures as mixing ratio and curing day, water contents of mixtures were measured after test. As a result, strength and $E_{50}$ were increased as mixing ratio and curing days, but values and tendencies of them appeared in different as kind of mixture, mixing ratio, curing method, and curing days. The results showed the addition of cement, lime, Fly Ash, and oyster soil in Bottom Ash could improved strength and $E_{50}$ and enlarge its field of being used.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2003.05a
• /
• pp.61-65
• /
• 2003

Bottom ash among the coal ash is not used because of its poor properties. But encouraging the use of bottom ash as a construction material is a sensible method of utilization as it avoids the problems and costs associated with disposal and provides an alternative aggregate source. This study was aimed at using bottom ash as an alternative fine aggregate source to provide a solution to disposal and insufficient fine aggregate for the production of concrete. So properties of domestic bottom ash were estimated due to the difference of each domestic bottom ash. And compressive strength and durability were estimated as basic data to use bottom ash in building industries. As a result of the experiment, the very porous surface and angular shape of the bottom ash particles necessitate a higher apparent water-cement ratio. And due to the higher water requirement, the compressive strength and durability of mortar is lower than those of the control samples. But when 25 percent of the total dry weight of the natural fine aggregate was replaced by bottom ash, the engineering characteristics were similar.

• Resources Recycling
• /
• v.5 no.3
• /
• pp.44-49
• /
• 1996

One of the most serious problems in utilizing the fly-ash produced from damcstic coal-firing power plants is lhc unburned-carbon mntained m the fly-ash In this shldy, the effects of fruther and collector an the yield,recuvery,unburnedcarbon rejectiou peiccntage,and process efficiency of product (cleaned fly-ash) wcrc examined when convzntional froth flotation was applied to rejcct the unburned-carbon included in the fly-ash of bituminous coal Alsa,the ash analysis for both thc raw and the clcaned fly-ash was conducted to review the change in thc major elements of fly-ash. Experimental results shawcd lhat tlle rcjectlon oI the unburned-cubon of thc raw fly-ash sample is available upto 92.4% using fiath flotalian and that the putity ol the pmdud(c1eancd fly-ash) attains up to 99.4%.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.49 no.3
• /
• pp.51-60
• /
• 2007

This study was performed to evaluate void ratio, compressive and flexural strengths, and pH properties according to the content ratio of rice husk ash, aggregate size, and neutral treatment time of porous concrete with content of rice husk ash produced as an agricultural by-product. The SEM results for cement mortar with a 5% rice husk ash for the weight of cement formed more C-S-H hydrates due to the $SiO_2$ of rice husk ash. In the XRD test, cement mortar with a 5% rice husk ash for the weight of cement registered a higher peak point of approximately $2{\theta}=20{\sim}25^{\circ}$ compared to cement mortar without rice husk ash. According to the results of the XRD and SEM tests, the $SiO_2$ that was a major chemical element of rice husk ash generated a large amount of calcium hydroxide in the early stage of the hydration process of cement leading to the formation of ettringite. The void ratio of porous concrete with rice husk ash decreased with increasing content ratio of rice husk ash. In addition, the void ratio of porous concrete with rice husk ash decreased compared to porous concrete without rice husk ash. The compressive and flexural strength of porous concrete with a 5% and 10% content ratio of rice husk ash slightly increased compared to concrete without rice husk ash. The pH value of porous concrete rapidly decreased immediately after neutral treatment. Then, it gradually increased and decreased again after 14 days. However, the pH value was nearly the same regardless of neutral treatment time in 28 curing days. Also, for neutral treatment, the pH value of porous concrete showed appropriate pH levels (less than 9.5) in all mixtures for planting at 28 curing days.

• Journal of the Korean Home Economics Association
• /
• v.43 no.8 s.210
• /
• pp.1-12
• /
• 2005

Ash solutions derived from vegetation have been known for their good mordanting action. They are used as finishing agents because they are able to promote dye uptake. It is expected that the types of ash solutions may have been different worker by worker since the workers have employed easy-to-get plants, when we reviewed old literature. However, the ash solutions are being used without clear distinctions between their characteristics. In this study, camellia ash solution and rice straw ash solution were prepared according to traditional methods. Using these solutions as mordanting agents, natural dyeing experiments with Caesdpinia Sappan were peformed. Following the dyeing procedure, the effect of the type of ash solution on the color of the dyed fabric was evaluated. The results showed that the ash solution mordanting effect us not dependent upon the components of the ash solution. It was also demonstrated that the mordanting effect was not based on the action of the metallic ions in the ash solution. The pH values of the ash solutions were adjusted in order to investigate the effect of changes in ash solution alkalinity on the dyeing process. The pH values ranged from neutral or weak acidity to the alkaline range in order to evaluate the characteristics of the mordanting tv the ash solutions.

• Resources Recycling
• /
• v.13 no.4
• /
• pp.3-10
• /
• 2004

The intension of this study is to produce ordinary portland cement using ash, both bottom ash and fly ash, obtained from municipal solid waste incineration ash (MSWI). We used limestone, waste molding sand, shale, slag from converting furnaces and fly ash as main raw materials and mixed them, setting the lime saturation factor (LSF) within 91.0, the silica modulus (SM) within 2.40, and iron modulus (IM) within 1.80. We conducted tests adding bottom ash alone 1, 2 and 3％ by weight, respectively, and a mixture of bottom ash 0.9％ and fly ash 0.1 ％ by weight. The result of analysis on clinker shows that the more ash is added, the lower the burnability index (B.I.) falls, lowering the mineral evolution of calcium silicate accordingly. From the measurement of compressive strength we have learned that the more ash is used, the lower the strength becomes.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 2002.05a
• /
• pp.91-96
• /
• 2002

본 연구는 화력발전소에서 발생하는 fly ash의 재활용 분야중 하나인 fly ash 경량골재 생산과정에서 소성(sintering)온도를 결정하는 미연탄소의 연소 현상을 분석함으로서 공정에 적용 가능한 단일 입자 연소 모델 개발을 목적으로 한다. fly ash 경량골재는 미연탄소를 포함한 fly ash를 점결제를 이용하여 성형하고, 함유된 미연탄소를 연소시켜, 그 연소열을 이용하여 fly ash를 소성 시켜 형성된다.(중략)

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.21 no.4
• /
• pp.99-107
• /
• 1979

In order to investigate the utilization of industrial waste and briquette ash for concrete production, briquette ash was used as fine aggregate for mortar production and three different kinds mortars were produced by mixing carbide and bottom aches with cement. These products were compared with mortar, produced by standard sand, in the respects of compressive, tensil and bending strengths. Further study on the economic aspect of utilization of briquette ash is needed but the results obtained from our preliminary study are summarized as follows : 1. The compressive strengths at the age of seven days of mortars, made of one to two ratios of cement to briquette ash, (cement+carbide ash) to briquette ash and(cement+bottom ash) to briquette ash were 70%, 61% and 58%, respectively, of the mortar made of standard sand. The compressive strengths of those mortars at the age of 28 days were 56%, 49% and 48% of the mortar made standard sand. 2. The compressive strengths at the age of seven days of the mortar made of one to two ratios of cement to briquette ash, (cement+carbide ash) to briquette ash and (cement+bottom ash) to briquette ash were 84%, 73%, and 70% of the mortar which was produced according to Korean Standard Value. The compressive strengths of those mortars at the age of 28 days were 85%, 73% and 73% of the mortar of the Korean Standard value. 3. The tensil strengths at the age of seven days of the mortars made of one to two ratios of cement to briquette ash, (cement+carbide ash) to briquette ash, and (cement+bottom ash) to briquette ash were 64%, 36%, and 36%, respectively, of the mortar of standard sand. The tensil strengths of those mortars at the age of 28 days were 70%, 47%, and 39%, respectively, of the standard mortar. The mortars made of one to two ratios of cement to briquette ash at the age of seven and 28 days were higher than the mortars of Korean Standard. The other mortars were 61 to 62% at the age of seven days and 75 to 90% at the age of 28 days of the Korean Standard mortar, respectively. 4. The bending strengths at the age of seven days of mortar made of one to two ratios of cement to briquette ash, (cement+carbide ash) to briquette ash, and (cement+bottom ash) to briquette ash were 46%, 53% and 50% of the mortar of standard sand. The bending strengths of those mortars at the age of 28 days were 90%, 77% and 69%, respectively of the mortar of standard sand. 5. The mortar of briquette ash which was lower in strengths compared with the mortar of cement have shown possibility of its secondary products of cement and concrete. The uses of briquette ash and industrial waste as construction materials would contribute toward solving various pollution problems caused by industrial wastes and saving labor costs needed to cleaning up. Furthermore, the effective use of briquette ash would greatly save the aggregate resources.

• Journal of the Korea Concrete Institute
• /
• v.11 no.6
• /
• pp.25-33
• /
• 1999

The role of fly ash in concrete become impotant with finding the charateristics of fly ash in which it is used as cement replacement material. An experimental study is carried out to investigate the characteristics of concrete containing fly ash. The loss of slump and air content of fly ash concrete tested up to 120 minutes are lower than those of ordinary concrete, but the setting time and bleeding are increased with increasing fly ash content. The compressive and tensile strength of fly ash concrete are slightly lower than those of ordinary concrete between 7 and 28 days, however, the long-term (at 180 days) compressive strength of fly ash concrete is significantly higher. In addition, fly ash reduces the heat of hydration and peak of temperature rise in concrete.