Hirota, Noboru

Kurachi, Mitsuo

Nishihara, Kiyokado

Kyoto University Research Information Repository

Title On the Leaching of Domestic Chromite Ore in Sulfuric AcidAuthor(s)Nishihara, Kiyokado; Kurachi, Mitsuo; Hirota, NoboruCitationBulletin of the Institute for Chemical Research, KyotoUniversity (1958), 35(5-6): 154-155Issue Date1958-03-30URL http://hdl.handle.net/2433/75607RightType Departmental Bulletin PaperTextversionpublisherKyoto University                            ABSTRACTS microdiffraction by Suito and Uyeda. The interplanar spacings of a-form copper-oxinate 2 hydrate calculated form X-ray diffraction patterns accord with the Hull and Daveys diagram for tetragonal system at the position of about 1.6 for c/a value. The interplaner spacings calculated, by assuming the cell constants as  a  =b  =6.57A, c =15.56A and a= S=6=90°, agreed with the above experimental results with accuracy of 1%.    It is concluded that a-form copper-oxinate 2 hydrate, which precipitates from the solution, transforms into stable (3-form, in the same way as in the case of copper-phthalocyanine.      On the Leaching of Domestic Chromite Ore in Sulfuric Acid           Kiyokado NISHIHARA, Mitsuo KURACHI and Noboru HIROTA                              (Sawamura Laboratory)      Transaction of the Mining and Metallurgical Alumni Association (Suiyo-Kwaishi). 13, 265 (1957)    To obtain a pure chromic sulfate electrolyte for the production of metallic chromium, the leaching conditions of a domestic ore (48.79 Cr203 and 12.69 FeO) in sulfuric acid containing small amount of (NH4)2Cr2O7 were studied.    Sample : The chromite ore from Numaoshi in Hokkaido was crushed by a Engelbach crusher, and sieved by a stuandare Tyler sieve.    Operation : Crushed ore was digested in 300-m1. porcelain beaker under atmospheric presssure, or in a 2-1 lean-lined autoclave under high pressure. A mixed solution of sulfuric acid and (NH.,)2Cr2O7 was used as leaching solution. After leaching the liquor was filtered. The amounts of Fe and Cr in the filtrate and precipitate were analysed.  Items of experiments :            Table 1. Optimum leaching conditions of Numaushi chromite.        Leaching conditionsUnder atomosheric press. Under high press  Size of ore (mesh)-200-200  Conc. of H2SO4 (%)70-8060 40 20   Leaching temp. (°c)150-170150 170 190  Pressure (kg/cm2)--3 7 11  Leaching time (hr)>2-- >4 --  Weight ratio of H2SO.1 to ore6.6-- 3 --   Weight ratio(NH.)2 Cr20;0.15-0.200.15' -0.20  Extraction of Cr(%)9090 ( 154 ) 1,BSTRACTS    Effects of leaching conditions on the extraction of chromium were studied. 1. Size of ore, 2. Leaching time, 3. A.mont of (NH4)2Cr2O7 added, 4. Leaching temperature, and 5. A.mont of charge.    Summary of Result : Results obtained are summarized in Table 1, which shows the optimum conditions for extraction of chromium.    If the acid concentration was increased up to 60%, insoluble brownish-yellow precipitate was formed in the presence of (HN4)3Cr2O7 in both cases of leaching.        Reaction of n-Hexyl Bromide with Potassium Fluoride                        in Several Glycols                  Hisao KJTANO and Ken-ichi Fuxui (Kodama Laboratory)  J. Chem. Soc. Japan. Ind. Chem. Sec. (KO gyo Kagaku Zasshi), 60, 272 (1957)    Reactions of n-hexyl bromide with potassium fluoride in isomeric propanediols and butanediols are studied. n-Hexylfluoride is obtained in high yields by the use of such glycols that have two adjacent hydroxy groups in the molecule. Two geome-trical isomers of 1,2-cyclohexanediols are used as the solvent. The yield of n-hexyl fluoride is ca. 30%' in the trans isomer, whereas it's only 2% in the cis isomer.                     Nitration of Desoxybenzoin                    Michiyasu SUGLIand Risaburo NAKAI                               (Nakai Laboratory)                      J. Org, Chem., 22, 288 (1957)    The reaction routes of desoxybenzoin with nitric acid (d=1.30) were studied by using C"-tracer technique. By the nitration of desoxybenzoin-carbonly-C' (I) (12.95,ec/m.mole) there were obtained p-nitrobenzil-carbonyl-C" (II) (12.92fec/m.-mole), benzil-carbonyl-C" (III) (12.96uc/m.mole), inactive P-nitro-benzoic acid (IV) and benzoic acid-carboxyl-C" (V) (11.29uc/m.mole). When treated with alcoholic potassium hydroxide, II decomposed into inactive p,p'-azoxydibenzoic acid, inactive p-nitrobenzoic acid and benzoic acid-carboxyl-C" (12.96,uc/m.mole). These facts indicate that the nitration occurs at the Para position to the methylene group of I.     The non-labeled specimens of p-nitrodesoxybenzoin, p-nitrobenzil, and benzil were treated with the nitric acid, respectively. p-Nitrodesoxybenzoin gave benzoic acid, p-nitrobenzoic acid, and p-nitrobenzil. Benzil and p-nitrobenzil, however, were resistant to nitration and oxydation, and were recovered without loss. The specific activity of V is comparatively lower than the theoretical value. These results would lead to the following conclusions. In the action of the nitric acid on desoxybenzoin-carbonyl-C", the p-nitrodesoxybenzoin-carbonyl-C" is formed as an intermediate, and its methylene group is oxidized to p-nitrobenzil-carbonyl-C". While oxidative disruption of the same intermediate gives benzoic acid-carboxyl-C" (155)

On the Leaching of Domestic Chromite Ore in Sulfuric Acid

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On the Leaching of Domestic Chromite Ore in Sulfuric Acid

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