• Journal of the Korean Wood Science and Technology
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• v.22 no.2
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• pp.54-60
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• 1994

The pine bark from mechanical pulp industry was cooked with bisulfite liquor, and the chemical and physical properties of the spent liquor after cooking for 90 minutes, which allowed partial defibration were determined. Lignosulfonate or lignin-related materials in the spent liquor have a molecular weight of approximately 3,000, which is lower than that of commercial lignosulfonate (C-LS) prepared from wood. The sulfonic equivalent weight calculated by colloid titration was 307 for C-LS, 238~239 for spent liquor. The contents of lignosulfonic acid and phenolic hydroxyl groups on $C_9$ unit of lignin in the spent liquor were 0.98~0.99, and 1.51~1.66, respectively. These values were remarkably higher than those of C-LS. Especially the content of phenolic hydroxyl group was almost twice that of C-LS. The viscosity of spent liquor after freeze drying was very low compared to C-LS. The dispersing ability of spent liquor was almost equivalent to or more than that of C-LS.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.4
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• pp.66-73
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• 2000

Alkaline sulfite-anthraquinone(AS-AQ) cooking process has been applied to unground pine bark. The properties of the spent liquor such as molecular weight distributions, sulfonic equivalent weights, degree of sulfonation, phenolic hydroxyl groups and kaolin dispersing ability have been investigated to evaluate the possibility of using this liquor as concrete additives or binders. In the case of ground bark meal, more than 90% delignification was achieved at the optimal cooking conditions. However, applying these conditions on unground bark the delignification was slightly retarded. The decrease in the degree of delignification may be attributed to less penetration and diffusion of chemicals during the cooking of the bark. Increasing the cooking temperature only by $5^{\circ}C$ improved the delignification of the bark and about 90% delignification can be achieved. These results indicate that bark can be used successfully during AS-AQ cooking without any mechanical or physical pretreatment. The properties of lignin or polyphenol sulfonates in the spent liquor after AS-AQ cooking of the bark were compared with Sunflo-R, which is commercial lignosulfonate(CLS) prepared from wood. The weight average molecular weights(Mws) estimated by gel-filteration chromatography was found to be ranging from 1,200~1,800. These are considerably lower than those in CLS. Lignin or polyphenol sulfonates in the spent liquor of bark and CLS have similar degree of sulfonation, but the phenolic hydroxyl group was 1.8 times higher than CLS. Moreover, the dispersing abilities of the spent liquors were better than that of CLS, especially after 0.1% addition to kaolin suspension.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.743-746
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• 1998

Pine bark waste was delignified with various sulfite liquors in order to use its spent liquor as concrete additives. The bark was easily deliginfied in alkaline sulfite-anthraquinone(ASAQ) cooking, resulting in more than 90% delignification. The dispersing ability of the ASAQ spent liquor was almost equivalent to or better than that of the commercial wood lignosufonate(CSL), Sanflo R.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.4
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• pp.74-80
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• 2000

A series of studies on nitric-acid pulping of municipal recycled waste papers were carried out to substitute the bleached chemical pulp imported for producing printing paper as well as to use its solidified spent-liquor as fertilizer. The first experiment was carried out to find the optimum treatment conditions such as pulp consistency, nitric acid charge and temperature in $HNO_3$-alkali pulping process. The results obtained were as follows: 1. Some selective delignification of OCC pulp was conducted by $HNO_3$-alkali process. The higher the temperature and concentration of nitric acid, the lower the pulp yield and kappa number of treated pulp. while its brightness was increased. 2. The higher consistency required the stronger mixing in case of more than 5% pulp. 3. In the laboratory, the suitable $HNO_3$-treating condition seemed to be less than 6% consistency, lower than 500% $HNO_3$charge on pulp and lower than $100^{\circ}C$ in cooking temperature. 4. The spent liquor with 1.77% N-content seemed to be slow-release nitrogen fertilizer suitable for agriculture.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.751-754
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• 1998

The study was carried out the efficiency of spent liquor(BSL) obtained from alkaline sulfite-anthraquinone cooking of pine bark added various surfactants. By adding surfactant to alkaline, weak alkaline, nertralized BSL, the dispersing ability of cement was remarkably improved. It was shown that the rate of water-reducing was 20~22%. The most superior efficiency surfactant was MTG. When BSL, MBSL and ABSL were added to MTG, the improvement of early and later strength was clear and also exhibited the superior properties of strength compared to PLAIN. Therefore, is a possibility that BSL will be used instead of melamine-base admixtures.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.747-750
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• 1998

The application of spent liquor(BSL) obtained from alkaline sulfite-anthraquinone cooking of pine bark to cement mortar significantly improved the water-reducing ability and decreased the rate of cement hardening. However, the compressive and flexural strength of BSL addition to cement mortar were lower than that of PLAIN. The application of 0.2% antifoamer to BSL slightly decreased water-reducing ability, but remarkably improved the compressive and flexural strength of cement mortar. On the other hand, BSL decreased the rate of hardening of cement, which exhibited the protperties of the lignosulfonated based retarding water-reducing type. but the setting time of cement could be controlled by addition of Na2CO3 could be used to convert BSL to normal or accelerating concrete admixtures.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.4
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• pp.42-48
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• 2001

The spent liquor (BSL) obtained from alkaline sulfite-anthraquinone (AS-AQ) cooking of pine bark was applied as a deinking agent. In the ONP deinking system, although BSL removed the small size of ink particles (${\geq}$$12.5{\mu}m$), it did not improve the brightness of pulp. The brightness of pulp slightly improved when treated with BSL at 150~$180^{\circ}C$. However, the brightness of the pulp was lower than that of a commercial deinking agent (oleic acid). It seems that BSL treated with a high temperature still had a high dispersing ability on the ink particles. Intensive oxidations were introduced, and remarkable deinking effects were observed at 13kgf/$cm^2$ oxygen pressure, $160^{\circ}C$ and 2h. When BSL treated at 13kgf/$cm^2$ oxygen pressure, $170^{\circ}C$ and a time period of 30~90 min is added to the pulp, at 0.1% or lower, the deinking effect became higher than that of oleic acid. On the other hand, additional alkali treatments during the oxidation possibility as a deinking agent when oxidized. However, since the oxidized BSL still has a high dispersing ability and lower molecular weight, several modifications need to be done in the near future in order to be applied as a high quality deinking agent.

• Resources Recycling
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• v.15 no.5 s.73
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• pp.3-10
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• 2006

The solvent extraction for the separation of platinum group metals from the leach liquor of spent automotive catalysts has been studied. Tri-n-butyl phosphate (TBP), tri-n-octylamine (TOA) and di-n-hexyl sulfide (DHS) were used as extractants and kerosene as a diluent. The extraction behavior of platinum, palladium and rhodium has been investigated as functions of different kinds of extractants and their concentrations. In addition, the extraction behavior of the major metal impurities such as cerium, lead, iron, magnesium and aluminum has been investigated. Platinum and palladium were extracted with TBP. And platinum, palladium and rhodium were extracted with TOA. Platinum was co-extracted with palladium into the organic phase by solvent extraction using SFI-6 of DHS extractant, but only palladium was selectively extracted with SFI-6R. The selective extraction of palladium with SFI-6R was found better than that with SFI-6, but the kinetics of extraction with SFI-6R was found poor in comparison to SFI-6. The metal impurities extracted simultaneously during the extraction of platinum group metals should be removed in scrubbing and stripping processes. A suitable process has been proposed for the separation of platinum group metals from the leach liquor of spent automotive catalysts. Initially palladium was extracted with SFI-6R, followed by the separation of platinum with TBP or TOA leaving rhodium in the raffinate.

• Resources Recycling
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• v.12 no.2
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• pp.36-44
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• 2003

The present work relates to the recovery of dissolved Mo from spent mandrel dissolving acid solution by injecting ammonia gas. In order to optimize the process parameters for high yield and high purity of recovered Mo products, a bench scale and a pilot scale experiments were carried out. As a result, more than 99.5% of Mo in spent acid was recovered in the form of ammonium molybdate(4MoO$_3$.$2NH_3$.$H_2$O). The purity of Mo products recovered was higher than 99.5%. In addition, the mother liquor, residual solution after precipitation and filtration of ammonium molybdate solid particles, could be utilized as fertilizers.

• Resources Recycling
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• v.20 no.3
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• pp.48-54
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• 2011

Sulphuric acid leaching was conducted to extract the metal values from spent refinery catalyst. More than 95% of Ni and V and 30% of Mo could be leached out in 1 M sulphuric acid and 1 hr of leaching time. The decrease in Mo leaching was due to typical characteristic of Mo matrix. The activation energies of the leaching reactions showed the dissolution process follows a diffusion control mechanism. In order to leach out all Mo, further the leaching experiments were conducted with sulfur free spent refinery catalyst. For sulfur free spent refinery catalyst, a two step process of leaching with 1 M sulphuric acid followed by sodium carbonate washing showed better leaching than a two step leaching process with sodium carbonate followed by sulphuric acid washing, with almost 99% leaching of Ni, Mo and V. Solvent extraction using LIX 841 were conducted for a leach liquor containing Ni, 2 g/L; V, 9 g/L, Mo, 0.6 g/L. More than 98% of Mo was extracted from the leach liquor at A:O ratio of 5:2 in a 2 stage process. Similarly V was extracted at A:O ratio of 5:3 in a 2 stage process with 82% of total V extraction.