<![CDATA[Bentonit adalah mineral yang cukup luas penggunaannya baik dalam bidang pertambangan maupun sebagai pengikat pasir cetak dalam bidang pengecoran logam. Secara alami bentonite ada dua jenis yaitu Na bentonite (swelling bentonite) dan Ca bentonite (non swelling bentonite). Melalui aktivasi menggunakan Na2CO3 terjadi pertukaran kation Ca oleh Na sehingga dihasilkan Na bentonite hasil aktivasi (activated Na bentonit). Penelitian ini dilakukan untuk menemukan karakteristik pembeda antara Na bentonite yang alami terhadap Na bentonite hasil aktivasi menggunakan berbagai metode karakterisasi yaitu XRD, SEM/EDS, pengujian indeks Swelling, titrasi, serta uji reaksi identifikasi. Na bentonite alami diberi kode sampel A, sedangkan Na bentonite hasil aktivasi diberi kode sampel AC. Hasil pengujian XRD menunjukkan bahwa pada bentonite alami tersusun atas senyawa montmorrilonit dan senyawa yang mengandung Al, Si dan O. Bentonite hasil aktivasi tersusun atas senyawa montmorrilonit dan kwarsa. Hasil pengujian SEM/EDS menunjukkan bahwa Na bentonite hasil aktivasi memiliki morfologi permukaan butiran yang lebih halus daripada bentonite alami. Na bentonite alami ternyata memiliki nilai indeks swelling lebih besar daripada Na bentonite hasil aktivasi. Indeks swelling Na bentonite alami berkisar antara 29 – 35 ml, sedangkan indeks swelling bentonite hasil aktivasi berkisar antara 15 – 22 ml. Hasil pengujian titrasi mengindikasikan bahwa pada Na bentonite hasil aktivasi mengandung anion CO32- lebih banyak berdasarkan volume asam HCl yang terpakai dalam titrasi yaitu 2-10 ml dibandingkan Na bentonite alami yaitu 0,5 – 1 ml. Reaksi identifikasi anion menunjukkan pada Na bentonite hasil aktivasi terjadi gelembung gas yang tidak ditemukan pada sampel Na bentonite alami.Kata kunci : Na bentonite, alami, aktivasi, morfologi, indeks swelling, gelembungPhysical and chemical characterization of bentonite to distinguish natural sodium bentonite from activated sodium bentoniteAbstrackBentonite is a mineral that widely used both in the mining sector and in the foundry industry as a molding sand binder. Naturally, there are two types of bentonite namely Na bentonite (swelling bentonite) and Ca bentonite (non swelling bentonite). Through activation using Na2CO3, Ca cation is exchanged by Na cation resulting in activated Na bentonite. The study was conducted to find the distinguishing characteristics between natural Na bentonite against activated Na bentonite using various characterization methods, namely XRD, SEM / EDS, Swelling index testing, titration, and identification reaction tests. Natural bentonite Na is designated as sample A, while activated bentonite Na is designated as AC. XRD test results showed that the natural bentonite is composed of montmorrilonite compounds and other compounds containing Al, Si and O elements. while the activated bentonite is composed of montmorrilonite and quartz. SEM / EDS test results that activated Na bentonite has a finer surface morphology than that of natural bentonite. Natural Na bentonite appears to have a swelling index value greater than that value of activated Na bentonite. The swelling index of natural Na bentonite ranges from 29 to 35 ml while it is of activated Na bentonite ranges from 15 to 22 ml. The result of titration test indicate that the activated Na bentonite contains more CO32- anions based on the volume of HCl acid used in the titration which is 2-10 ml compared to natural Na bentonite which is 0.5-1 ml. Anion identification reaction shows that gas bubbles appear in activated Na bentonite while it did not in natural Na bentonite sampel.]]>
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