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Volume 44 (1990)
- Issue 6 Pages 355-
- Issue 5 Pages 301-
- Issue 4 Pages 235-
- Issue 3 Pages 159-
- Issue 2 Pages 93-
- Issue 1 Pages 5-
Volume 44, Issue 4
Displaying 1-7 of 7 articles from this issue
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Shinichi NAKAO1990 Volume 44 Issue 4 Pages 235-247
Published: 1990
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSDownload PDF (8006K) -
Naohito YOSHIKAWA, Masami HASEGAWA1990 Volume 44 Issue 4 Pages 248-256
Published: 1990
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSAs the ratio of sodium chloride content to total salts increases in the advanced technology that lowers the permeability of bivalent ions through ion-exchange membranes, it has resulted in increase of the potassium content and decrease of the magnesium content in the produced common grade salt.
For that reason, it is presumed to be difficult to meet the quality conditions of the salt, which are below 0.25 percent as the standard content of potassium and above 0.04 as the ratio of magnesium to moisture (Mg/H2O ratio) for prevention of blocking. Therefore, it is significant to examine the methods of operation of crystallization in order to maintain the quality of products. In this study, the quality of the common grade salt affected by increasing the ratio of sodium chloride to total salts was discussed in relation to the computer simulation, and the methods of operation to satisfy the quality were discussed.
The results were as follows.
1) Cooling the sprinkled bittern over crystals from the temperature in the pan for concentrating mother liquid to 30 degrees decreased the content of potassium in products in the range of 15.7 to 46.9 percent.
2) Increasing the replacement rate from 50 to 100 percent increased the Mg/H2O ratio in products in the range of 15.6 to 41.2 percent.
3) Increasing the concentration ratio from 100 to 120 percent increased the Mg/H2O ratio in products in the range of 13.3 to 21.8 percent.
4) The examination of the cooling temperature of the sprinkled bittern satisfied the quality condition of the content of potassium.
5) It is necessary to build the pan for concentration of the bittern and to examine the replacement rate and the concentration ratio of the bittern in order to satisfy the quality condition of the Mg/H2O ratio.View full abstractDownload PDF (5850K) -
Sadanobu INOUE, Tadashi TAKAHASHI, Mutsuya MATSUBARA1990 Volume 44 Issue 4 Pages 257-261
Published: 1990
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSA simple and sensitive method for the spectrophotometric determination of molybdenum in seawater was studied. Molybdenum could be quantitatively and selectively extracted with α-benzoin oxime into chloroform from 0.1 moldm-3 hydrochloric acid solution. Chloroform phase was trans ferredin another vessel and was evaporated to dryness. Then sensitive color-producing reagent, dimethylaminophenylfluorone (DMAPF), solution to form a molybdenum-DMAPF complex by the ligand exchange reaction between molybdenum-α-benzoinoxime complex and DMAPF in the presence of cetyltrimethylammonium bromide, was added to the evaporated residue, that is, molybdenum-α-benzoinoxime complex. Molybdenum was determined in coastal sea-water collected at Abashiri harbor, and the result obtained was 10.1μgdm-3, which was in agreement with the reported value.View full abstractDownload PDF (3138K) -
Katsuya UESUGI, Tsutomu MORIE, Tetsu KUMAGAI, Tohru NAGAHIRO1990 Volume 44 Issue 4 Pages 262-266
Published: 1990
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSA micro amount of vanadium contained in common salt was determined by graphite furnace atomic absorption spectrophotolnetry in conjunction with extraction technique. Vanadium is reacted with 3, 5-dibromosalicylaldehyde-2-benzothiazolylhydrazone (BSTH) to form a stable complex in the presence of zephiralnine, which is extracted into chloroform and then back-extracted with a small amount of hydrochloric acid into aqueous phase. Vanadium concentrated in aqueous phase is determined by graphite furnace atomic absorption spectrophotometry. The optimum conditions on the extraction and the back-extraction for concentration of vanadium were examined. Micro amount of vanadium was quantitatively extracted into 10ml of 5.0×10-4 MBSTH chloroform solution in the presence of zephiramine from aqueous solution at pH3.8, by shaking 10min. And then extracted complex was back-extracted with 0.5ml of 3.5 M hydrochloric acid into aqueous phase. When a known amount of vanadium was added to the common salt samples, vanadium was recovered satisfactorily. The proposed method has been successfully applied to the determination of micro amount of vanadium in colnmon salt. The method is simple, rapid, and sensitive for the determination of vanadium.View full abstractDownload PDF (3161K) -
Ramesh CHITRAKAR, Masamichi TSUJI, Mitsuo ABE, Kenji HAYASHI1990 Volume 44 Issue 4 Pages 267-271
Published: 1990
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSAntimonates of Sn (IV) and Ti (IV),λ- and cryptomelane type-MnO2, hydrotalcite, hydrous oxides of Ti (IV) and Zr (IV), crystalline antimonic (V) acid (Sb2O5·4H2O), and α-Zr (HPO4)2 were studied for selective uptake of lithium from seawater by the batch and column methods and the extraction features were compared. Among these inorganic ion exchangers studied, metal antimonates exhibited the most effective uptake of Li+ from seawater.View full abstractDownload PDF (3373K) -
Akihiro GOTOH, Humikazu IKAZAKI, Mitsutaka KAWAMURA1990 Volume 44 Issue 4 Pages 272-274
Published: 1990
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSPreparation of crystalline sodium chloride ultrafine particles is carried out by drying the fog of thin sodium chloride solution produced with an ultrasonic nebulizer.
Problems that occurred in the preparation procedures are studied and discussed. The followingresults are obtained.
1) Sufficient amount of approx. 150°C dry air against that of the spray must be mixed to produce stable cubiccrystalline ultrafine partides.
2) Raising the temperature of dry air for production of high concentration of ultrafine particlesin air often results in the production of hollow particles.
3) One of the methods for producing much finer particles is the use of thinner sodium chloridesolution to spray. However, it was found that ultrafine particles are never produced by using a thinner sodium chloride solution less than approx. 1ppm.
4) Provided that the particle size of fog produced becomes much smaller, we could prepare the smaller sodium chloride ultrafine particles.View full abstractDownload PDF (2106K) -
Dennis S. KOSTICK1990 Volume 44 Issue 4 Pages 275-290
Published: 1990
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSDownload PDF (7721K)
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