The desicant production from sepiolite

Within the context of this study, the sepiolite samples with different physico chemical properties obtained from Sivrihisar area were investigated for their usability as desicant and also for enhancing their desicant feature with various tests. Five samples were selected for this test but the investigations were major on three of these samples because of their higher sepiolite content than the other two.Firstly, to determine the desicant size, the samples were examined for their humidity absorb capacity according to size aparture. After that, thermal activation effect on samples for their humidity absorb capacity was investigated. Thermal activation tests were done under 90-105-150-200-250-300-350-400-500 oC . The reason for exposing sepiolite under thermal process is to increase their humidity absorb capacity in paralel with the increase of specific surface area. The humidity absorb capacity was increased to 300 0C but over this temperature decreases for humidity absorb capacity were observed. As a result of removing structural and zeolitic water the specific surface area was increased and in paralel with these increment the humidity absorbance capacity was increased until 200 0C. But when that temperature became over 300 0C the humidity absorbance capacity was decreased in parallel with souring of micropores.Therefore, 200 0C was accepted as activation degree as the best humidity absorbance capacity was observed about 200 0C.For, increasing the humidity absorbance capacity of sepiolite, firstly the impruties were removed with hydrocyclone tests. an increase was observed on humidity adsorbance property of products obtained from tests, but that increase was not accepted as sufficient.In USA and Japan standarts, to be used as humidity adsorbance ( a desicant material) ,sepiolites should to adsorb at 25 0C at 20,50 and 90 % humidity . Therefore, to increase the humidity adsorbtion capacity of sepiolites ,mixtures were prepared by adding CaCl2,MgCl2, LiCl ,NaSO4 ,similar salts and reactives to the sepiolite samples at 10%w.It was observed that these salts increase humidity adsorbance degree in this order LiCL>CaCl2>MgCl2>NaSO4. On the other hand NaSO4 decreases the humidity adsorbtion of sepiolite. As a result sepiolite suitable for standars was obtained by adding %3 LiCl ,%5 CaCl2 and %7 MgCl2. Also the effect of temperature on humidity adsorbance of sepiolites was investigated. It was found that sepiolite humidity adsorbance capacity was in paralel with increasing temperature but after 40 0C it started to decrease. That situation decrease by increasing the CaCl2 for CaCl2 added sepiolite samples.Keywords: Sepiolite, Desicant, Temperature, Inorganic salt, Relative humidity.