简介:CalciumhydroxytitanateformedinBayerdigestionprocessofchinesediasporicbauxitewasstudied.InterplanarspacingsofcalciumhydroxytitanatecrystalweredeterminedbyXRDanalysis.Onlyoneendothermicpeakoccursat550~560℃ontheDTAcurveofthiscompound.IRspectrometrystudyhasrevealedthathydroxyldoesexistincalciumhydroxytitanateinsteadofcrystalwater.ObservationunderSEMhasindicatedthatitscrystalgrainsareintheshapeofregularhexagonalplateswith2~8μminedgelengthandlessthan1μminthickness.TheinfluencesofvariousdigestionconditionsontheformationandtransformationofcalciumhydroxytitanateandotherCa-Ti-containingcompounds,suchaslimeaddition;contentanddistributionstateofTiO2inbauxite;digestiontemperatureandretentiontime,werefurtherstudied.
简介:Fromaneconomicalpointofviewboththequalityoftheionexchangeresinsandthetechnologyusedinthefieldofindustrialwatertreatmentareimportantforasuccessfulperformance.Ingeneral,twodifferenttechnologieshavebeenestablishedonthemarket:ThemaindiffernecesbetweentheCO-andcountercurrenttechnologeswillbediscussedanddataconcerningtherequirementofchemicalsforregenerationandthequalityofthedeionizedwaterwillbeopposed.Inadditionseveraldifferentvarietiesofthemoderncountercurrenttechnologies,developedandpatentedbyBayerAG,willbedescribedandtheadvantages,dependingontheapplicationandthedemandonthequalityofthedeionizedwater,pointedout.Inviewofstrongerregulationsconcerningtheconsumptionofregenerationchemicals,andwastewater,andalsobecauseofthesuperiorqualityoftheproducedwater,themarketshareofcountercurrenttechnologieswillcontinuetoincreaseworld-wide.