Abstract
Aluminumhydroxy-smectite (AHS), known also as pillared clay, has some specific characteristics such as wide specific surface area, high basal spacing, and stable at significant high temperature. The AHS was produced from smectite and polymer aluminumhydroxy. In the industrial sector, this product can be used as cracking-catalyst, absorber, and molecular sieve up to 500°C. A similar product can be constructed from vermiculite, and the aluminumhydroxy-vermiculite (AHV) is predicted to have better thermal stability than AHS due to a higher charge density of vermiculite that adsorbs more aluminumhydroxy than that of smectite.Related to the above background the objectives of the research were to study the effects of cation valence in the interlayer space of vermiculite using Li and Ml ions in the formation process and the chemical characteristics of AHV. Li and Mg-vermiculites with different particle sizes are reacted with polymer aluminum-hydroxy' at 100 °C temperature. Solution of 2% Locron was used as a source of aluminum-hydroxy. The products were characterized by chemically and mineralogica/~v. The chemical characteristic includes total chemical analysis, whereas the mineralogical characteristic comprises basal spacing identification that was measured with an X-ray diffractometer (XRD). The results indicated that the AHV produced from Li-vermiculite showed peaks of 1.86 nm and 1.41-1.45 nm with increasing intensity of the 1.86 nm peaks as the particle size was finer. The AHV produced from Mg-vermiculite showed only a peak of 1.45 nm, whereas the 1.84 nm peak can on~v be identified as a shoulder. The AHV with a peak of 1.86 nm (AHV-I.86) can keep its basal spacing to 1.68 nm after 3 hours of heating at a temperature of 700°C, whereas the AHV-I.45 nm shrinkages to 1.10/0.98 nm at the same treatments. Chemical analysis showed that the inter/oyer space of the AHV-I.86 consists of more aluminum-hydroxy than that of the AHV-I.45. Ratio o(OH/AI o(the interlayer aluminum-hydroxy in the AHV-1.86 was 2.57, whereas that of the AHV-1.45 was 2.40.
 Keywords: Aluminum hydroxy-smectite, aluminumhydroxy-vermiculite, a pillared clay, polymer aluminumhydroxychloride, smectite. vermiculite
Highlights
Aluminumhydroxy-smectite (AHS), known as pillared clay, has some specific c...haracteristics such as: wide specific surface area, high basal spacing, and stable at significant high temperature
Liand Mg-vermiculites with different particle sizes are reacted with polymer aluminum-hydroxy' at 100°C temperature
The chemical characteristic includes total chemical analysis, whereas the mineralogical characteristic comprises basal spacing identification that was measured with X-ray diffractometer (XRD)
Summary
Vermikulit yang digunakan adalah vermikulit "Russland" dari Firma Thermax, Austria. Setelah mineral digiling dengan penggiling, kemudian dihaluskan lebih lanjut dalam air dengan bantuan Ultraturrax. Larutan segar Locron 2 % (setara dengan 5.1 mg AI mrl dengan pH sekitar 4.6-4.7) cocok digunakan untuk membentuk aluminiumhidroksi-vermikulit (Iskandar dan Reichenbach, 1993). Aluminiumhidroksi-vermikulit dihasilkan dengan cara sebagai berikut: 50 ml larutan Locron 2% dipanaskan dalam erlenmeyer 100 ml selama JO menit di atas penangas air 100 DC. Selanjutnya sebanyak 500 mg vermikulit yang telah dijenuhi dengan Mg2+ ataupun Lt dimasukkan ke dalam larutan Locron panas tersebut. Aluminium hidroksi-vermikulit yang dihasilkan dicuci dengan aquadest berulangkali sampai bebas khlorida (uji AgN03), disaring dan dipanaskan dalam oven pada suhu 60 DC. Analisis kimia dilakukan dengan m~ncampurkan contoh yang telah dikeringkan pada 300 DC dengan campuran pekat HCI04 dan HF, dan didiamkan semalarn di atas penangas pasir pada suhu sekitar 240 DC. Kadar Fe2+ ditetapkan dengan melarutkan contoh dengan campuran pekat HF dan H2S04 di atas penangas pasir pada suhu sekitar 100°C selama 10-15 menit. Unsur Si ditetapkan secara spektrofotometri menggunakan ammonium molibdat (Hermann, 1975 dan Hallmark el al., 1982)
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