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All Journal Indonesian Journal of Pure and Applied Chemistry
Imelda H Silalahi
Universitas Tanjungpura
Biochemistry, Genetics & Molecular Biology Chemistry

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KOMPOSISI UNSUR DAN KARAKTERISTIK MINERAL PASIR PUYA DARI SINTANG, KALIMANTAN BARAT (ELEMENT COMPOSITION AND MINERAL CHARACTERISTIC OF PUYA SAND FROM SINTANG, WEST KALIMANTAN) Duwan Agustina; Risa Nofiani; Imelda H Silalahi
Indonesian Journal of Pure and Applied Chemistry Vol 4, No 1 (2021)
Publisher : Tanjungpura University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (734.898 KB) | DOI: 10.26418/indonesian.v4i1.45758

Abstract

Puya sand is a byproduct from local gold mining activities found in Sintang, West Kalimantan. Puya sand is usually left by the miners after the mining activity leaving a pile of abandoned sands. Mineral characterisation conducted by using XRD and XRF methods demonstrated that the sand contains valuable elements and mineral, i.e. zircon silicate, quartz and ilmenite. A simple physical flotation separation method removed quartz remaining material containing concentrated zircon silicate. XRD analysis by using Search-Match followed by amount calculation by using Rietveld refinement showed that the sand consists of zircon silicate (58.3%), ilmenite (35.2%) and anatase (6.5%). Elemental analysis by using XRF presented the percentage of Zr, Ti, Fe and Si is 41.0, 23.9, 13.06 and 8.3, respectively. Hafnium with 1.5% was also observed along with Th, U and rare earth elements (REEs), such as Nd, Y, Eu, and Yb.
FOTODEGRADASI FENOL DALAM LEMPUNG TERPILAR TIO2 (PHOTODEGRADATION OF PHENOL ON TIO2-PILLARED-KAOLINITE Imelda H Silalahi; Nelly Wahyuni; Irwan Irwan
Indonesian Journal of Pure and Applied Chemistry Vol 3, No 2 (2020)
Publisher : Tanjungpura University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (780.548 KB) | DOI: 10.26418/indonesian.v3i2.46491

Abstract

Photodegradation of phenol on TiO2-pillared-kaolinite was observed. Pillarization of kaolinite was conducted through intercalation of polyoxotitanium sol into clay suspension followed by calcination giving TiO2-kaolinite which showed an increase in specific surface area and total pore volume compared with the kaolinite. The analysis of XRD demonstrated no significant change on d-space of second order of kaolinite structure associated with 2q 26.61°, but diffractions with regard to 2q 25.3° and 48.0° interpreted for TiO2 anatase were seen on the diffractogram of TiO2-kaolinite. The significant decrease of phenol concentration was observed in the presence of both kaolinite and TiO2-kaolinite under UV illumination (hn  ³ 365 nm) compare with the photoreaction without the kaolinite materials however the degradation rate of phenol on TiO2-kaolinite was faster than that on the kaolinite-only where 50% of phenol was consumed after 45 minutes of reaction. Kinetic study showed the photoreaction of phenol on TiO2-kaolinite follows the first order reaction with the reaction rate constant of 1.8 x 10-2 min-1.
Co-Authors Duwan Agustina Irwan Irwan Nelly Wahyuni Risa Nofiani