摘要:

AbstractA low‐temperature tar was sub‐divided, entirely by solvent extraction, into the following fractions: crude phenols and bases; hydrocarbons of different types—aliphatic, hydroaromatic and aromatic; and a neutral, oxygen‐containing aromatic fraction. The three hydrocarbon materials and the last‐named were obtained from the neutral tar oil (light petroleum‐soluble) by a series of partition extractions with the solvent pair, furfural/light petroleum, petroleum, using definite ratios of tar/solvents. These four fractions corresponded closely to those previously obtained by adsorption chr

ISSN:0021-8871    

DOI:10.1002/jctb.5010160401

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractThe recrystallisation behaviour of melts and glasses derived from beryl ores, flotation concentrates and synthetic oxide mixtures was examined and two new hybrid beryllium aluminium silicate phases were discovered. Beryllium extraction from the various products was correlated with their heterogeneous structure and conditions were established which enabled more than 95% of the beryllium to be extracted from all the ores and concentrates examined.

ISSN:0021-8871    

DOI:10.1002/jctb.5010160402

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractThe reaction between kaolinite and neutral and acid sodium fluoride solutions was investigated at different temperatures and over the acid pH range.The stoicheiometric replacement of hydroxyls in the kaolinite crystal lattice by fluoride ions, as reported by earlier workers, was not confirmed. The release of hydroxyl ions into solution was due predominantly to the disruption of the kaolinite crystal lattice. In the presence of sodium ions and at pH7, only cryolite was found as a solid phase. Small, spherical, particles were observed in all cases. These particles were believed to be amorphous silica, formed as an intermediate phase in the disruption proces

ISSN:0021-8871    

DOI:10.1002/jctb.5010160403

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractThe dissolution of kaolinite in aqueous solutions of hydrofluoric acid was investigated at different temperatures and fluoride concentrations. The percentage dissolution of kaolinite was greater than was to be expected from a theoretical consideration of the reaction. The percentage dissolution was less for Na‐kaolinite than for a H‐kaolinite under the same experimental conditions. Two reaction rates were observed. The relative intensities of the 001 and 002 basal reflections decreased with reaction time, temperature and hydrofluoric acid concentration. The decrease was probably due to an amorphous phase. Although kaolinite samples after treatment at the lower temperature showed very little change in their infra‐red absorption spectra, a marked change in the spectra was observed at the higher temperature. The disruption of the kaolinite crystal lattice is believed to be due to the preferential extraction of aluminium from the lattice leaving an intermediate silica phase, which dissolves to form fluorosilicic

ISSN:0021-8871    

DOI:10.1002/jctb.5010160404

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractA fluoro‐complex of aluminium is selectively precipitated by sodium ion from a dilute aqueous solution aluminium, beryllium, fluoride and potassium ions at a pH near 3. Subsequent flotation of this precipitate with long‐chain alkylamines is affected by carbon chain length, pH, concentration of fluoride ion, rate of gas flow into the flotation cell and micellar form of the collector. Temperature has little effect on recov

ISSN:0021-8871    

DOI:10.1002/jctb.5010160405

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractBlackband ironstone and siderite have been separately decomposed in a fluidised bed of sand in an atmosphere of nitrogen and the progress of reaction followed by a ‘volatile matter’ test. For the ironstone in the temperature range 370–570°, the residual volatile matter (VR) after a time (t) between 10 sec and 60 min. was given by the expressionVR= A – B logt, where A and B are constants for a given temperature. The kinetics of decomposition of siderite at 455 and 485° were first‐order with an activation energy of 51 kcal. /mole. It is concluded that blackband ironstone appears to decompose by a large number of independent first‐order reactions having a range of activation energies showing a peak frequency

ISSN:0021-8871    

DOI:10.1002/jctb.5010160406

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY