• Resources Recycling
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• v.6 no.1
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• pp.40-46
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• 1997

Sludgc d~sposal has been a major challenge in the wastewater treatment. Drying is operation which is separated fromsewage sludge to solid and liquid by heating. Drying needs to pretreatment process for effective "thation, incinerationand dispaal The objective of this work was to the drying dewatered sewage sludge by microwave heating, and tocompare the experimental rcsults with thcorctical rcsults. Microwave drylng is fast and has a high efficiency. In thepresent \ark, an unsteady state analysis of one dunensional drying, with microwave heating, is carried out. In drying ratecurve, moisture movement at falling rate period occured by dfision. A good agreement was abtamed between the modcland the experimental results using the slab sample of 0.2cm thickness. 0.2cm thickness.

• Resources Recycling
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• v.10 no.4
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• pp.24-33
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• 2001

For making a high degree of efficiency, this study attempts to gather each arisen-sludge from experiments and examine into its characteristics, in order to compare the biological reason of removing phosphorus with sintered body using calcite and the artificial reason of removing with a chemical reagent. First, it can be seen that sludge, which is identified CaCO$_3$, of 0.1∼0.2$\mu$m is regularly formed when using sintered body, calcite. And it is one of the results of the chemical methods in order to remove phosphorus that can be seen that sludges of 100∼50 $\mu$m are formed and that the forms of Ca$_2$P$_2$O$\_$7/, Ca$_3$(PO$_4$)$_2$$.$nH$_2$O, $\beta$-Ca$_2$P$_2$O$\_$7/ are shown when using a reagent, CaO dissolved water. The other of the results of the chemical methods can be seen that a lumpof sludge is formed when using wastewater and a reagent Ca$^2$$\^$+/ are used, and that the lump consists of Ca$_3$(PO$_4$)$_2$$.$nH$_2$O와 Ca$_2$H$_2$P$_4$O$\_$14/.

• Resources Recycling
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• v.4 no.1
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• pp.12-19
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• 1995

This study was carried out to remove the iron and impurities usmg hydrocyclone and HGMS for recycling of sludge from the granite stone cutting and polishing industrγ in the basic of chemi떠1 analysis and minerallogical investigation. This sludge consist of 70.9% $SiO_2$ 13.6% $Al_2O_3$ and It also contained 2.52% of $Fe_2O_7$ and 0.29% of $TiO_2$, as a main impurities to decrease the whiteness. As the result of hydrocyclone experiment, It was very good condition that are 100~150 g/l of sludge amount, 2.0~ 2.5 mm of underflow nozzle size, and 1.2~1.6 kg/$\textrm{cm}^2$ of pressure for 85% sludge product with the $-37{\mu}\textrm{m}$ size. $Fe_2O_3$ and $TiO_2$, contents by treatment of HGMS were decreased with 0.65% and 0.07% each at 10,000 gauss of magnetic field strength, and addih$\upsilon$n of Sodium tripolyphosphate as a dispersant was effected to get low grade F Fe,Ol and TiO, concentrate. PhYSIcal properties of this stone sludge product were showed 58.5% of whiteness, 1 13.4% of firing shrinkage and 3.0812 $\textrm{m}^2$/g of specific surface area.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.105-111
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• 2004

When the clitellate tiger worms(Eisenia fetida) were fed with paper mill sludge, sewage sludge of agricultural-urban area and sewage sludge of agricultural area, number of cocoons produced by individual clitellate earthworm for 104 days were 11.8, 8.6 and 3.5, respectively. However, clitellate earthworms that had been fed with sewage sludge of agricultural-urban area for 52 days or fed with sewage sludge of agricultural area for 95 days could not produce cocoons, whereas the earthworms that were fed with paper mill sludge kept producing cocoons through the investigating period. The hatchability of cocoons produced by the clitellate tiger worms(Eisenia fetida) fed with sewage sludge of agricultural-urban region, sewage sludge of agricultural region and paper mill sludge were 42.8%, 38.3% and 39.2%, respectively. And hatching periods of cocoons were 33.8~36.0 days, which were not affected by the kinds of sludges. However, the cocoons produced by clitellate earthworms which had been fed with sewage sludge for about 1.5 months could not hatch at all. Death rates of second generation hatched from cocoons produced by tiger worms(Eisenia fetida) which had been fed with the sewage sludge from agricultural-urban region and the sewage sludge from agricultural region reached to 100% and 90% at 60 days after hatching, respectively, whereas death rate of second generation fed with paper mill sludge reached to 16%.

• Resources Recycling
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• v.31 no.6
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• pp.60-65
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• 2022

This study presents the carburization process for recycling sludge, which was formed during silicon wafer machining. The sludge used in the carburization process is a mixture of silicon and silicon carbide (SiC) with iron as an impurity, which originates from the machine. Additionally, the sludge contains cutting oil, a fluid with high viscosity. Therefore, the sludge was dried before carburization to remove organic matter. The dried sludge was washed by acid cleaning to remove the iron impurity and subsequently carburized by heat treatment under vacuum to form the SiC powder. The ratio of silicon to SiC in the sludge was varied depending on the sources and thus carbon content was adjusted by the ratio. With increasing SiC content, the carbon content required for SiC formation increased. It was demonstrated that substoichiometric SiC_x (x<1) was easily formed when the carbon content was insufficient. Therefore, excess carbon is required to obtain a pure SiC phase. Moreover, size reduction by high-energy milling had a beneficial effect on the suppression of SiC_x, forming the pure SiC phase.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 1993.03a
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• pp.22.2-22
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• 1993

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2001.05b
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• pp.141-144
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• 2001

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.146-147
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• 2014

The environmental pollution problem the globally related to global warming arises, the demand for the solar power generation increases. But is generated sludge about 2tons in order to produce 1ton in the solar power generation used main material polysilicon. In this way, the arising sludge there is not method recycling and it is all discarded. Therefore, in this research, cement is not used dynamic properties tries to be analyze inorganic binder based on blast furnace slag and polysilicon sludge ratio. The appropriate replacement ratio of the experimental result polysilicon sludge was to be 8%.

• Resources Recycling
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• v.19 no.4
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• pp.51-57
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• 2010

As a recycling of Si sludge from Si wafer process, a Si-SiC-CuO-C composite material was synthesized and investigated as an anode material for lithium batteries. The Si sludge consisted of Si, SiC, machine oil, and metallic impurities. The oil and metal impurities was removed by organic washing, magnetic separation, and acid washing. The Si-SiC-CuO-C composite from the recovered Si-SiC mixture was prepared by high-energy mechanical milling. According to the electrochemical tests such as charge-discharge capacity and cycling behavior, it showed the improved cycle performance. The SiC and CuO-related phases were presumed to restrain the volume expansion of the anode and Fe, however, should be removed below 10 ppm prior to synthesis of the composite because it caused the capacity loss of the active material itself.

• Clean Technology
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• v.8 no.2
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• pp.61-66
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• 2002

Recycling method of red mud, byproduct from the aluminium manufacturing process, and paper sludge was investigated in order for them to be utilized as the adsorbent for the removal of volatile organic components(VOCs). Either high density polyethylene(HDPE) or low density polyethylene(LDPE) was added to facilitate the manufacture of adsorbents. The utilization of HDPE in the adsorbents increased the adsorption capacity due to the good physical properties, such as, BET and true density, compared with LDPE. BET values of the manufactured adsorbents were much lower than the commercial activated carbon ($10^{-2}-10^{-3}$). It may be due to the fact that the time for decomposition of the paper sludge was not enough during the manufacturing of adsorbents. But the specific adsorption capacity of the manufactured adsorbents (mole adsorbed per unit surface area) had much higher value than the commercial activated carbon (10-100). Therefore, it is important that BET of manufactured adsorbents needs to be increased to obtain the same adsorption capacity as the commercial activated carbon.