ADSORPTION AND FLOCCULATION BEHAVIORS OF ILMENITE AND FELDSPAR IN THE PRESENCE OF SULPHONATED POLYACRYLAMIDE——Experimental

The adsorption of Sulphonated polyacrylamide(PAMS)on ilmenite and feldspar fromaqueous solution and the floeculation of minerals by PAMS have been studied.The researchresults reveal that the strong adsorption of PAMS on ilmenite results in its strongflocculation and the weak adsorption of PAMS on feldspar causes its dispersion to be morestable.The mechanism of PAMS bonding is discussed in terms of co-ordination and H-bonding interaction respectively in the light of molecular orbit.The co-ordination between—So_3~- on PAMS chain and sites of Ti~(4+) or Fe~(2+) on ilmenite was testified by electron spec-troscopy(PHI550ESCA/AES).Consequently new technology“Bulk flocculation-magneticsepa-ration-ultrasonic deflocculation-magnetic separation”for fine ilmenite/titano-magnetite/feld-spar system has been successfully developed.     

THE POLYELECTROLYTIC BEHAVIOURS OF ACIDIC AQUEOUS SOLUTIONS OF CHITOSAN IN THE PRESENCE OF EXTERNAL SALTS

The viscosities of chitosan-HAC in aqueous solution with various amount of NaAC have beenmeasured.Based on the analysis of experimental data,an empirical equation is deduced to des-cribe the relationship between the intrinsic viscosity and the concentration of external salt in thechitosan solution:[η]=[η]_∞+P/m~nand another empirical equation is proposed for describing the variation of reduced viscosity ofchitosan solution as function of salt and chitosan concentrations:(η_(sp)/c)_(salt)={D+A/(1+BC+HC~2)}·{1-1/(([η]_m=0)/([η]_(m=0)-[η]_∞)+P/m~R)+(C~/m~)}where the first term represents the relationship between viscosity and polymer concentration in theabsence of external salt,while the second term represents the correction value on viscosity in thepresence of external salt.     

CHARACTERISTICS OF LIGNIN REACTIONS IN SODA COOKING OF WHEAT STRAW PART 1 REACTION OF UNCONDENSED LIGNIN

INTRODUCTIONWheatstrawisanimportantfiberrawmaterialinmanycountries熏particularlyinAsia熏EasternEurope熏andLatinAmerica熏whereareshortofwoodsuppliessuitableforthepurpose.Ithasbeenreportedthatnon-woodplantfiberswillplayanincreasingroleintheglobalpulpandpaperindustry熏andtheworldstrawproductionwasapproximately10熏000milliontonsin1998眼1演.ThelargestcapacityforproducingpulpfromthestrawisconcentratedinChina.IntheEuropeanCommunitythereisalsoagrowinginterestinthedevelopmentofnon-foodapplicati…     

SOME INVESTIGATIONS ON THE NATURE OF REACTION PROCEEDING OF RADIATIONINDUCED GRAFTING IN THE POLYETHYLENE AND ACRYLIC ACID SYSTEM

Direct radiation grafting of acrylic acid (AA) and methacrylic acid (MAA) onto polyethylene (PE) films was studied. The investigation of the nature and characters of grafting proceeding was performed. The penetration of grafting onto the thin PE film was studied and the mechanism discussed. This involves an initial stage whereby the grafted surface layer deforms the PE allowing further monomer to penetrate. It was shown that the surface grafting was dynamic controlled and the penetration of monomer depended on the polarity of monomer.