Sintesis Magnesium Oksida (MgO) dari Dolomit Bangkalan dengan Metode Leaching

Synthesis of Magnesium Oxide (MgO) from Dolomite Bangkalan by Leaching Method

Magnesium oksida (MgO) merupakan material keramik yang memiliki potensi dalam bidang medis dan industri, dimana MgO dapat diperoleh dari bahan alam dolomit yang memiliki komposisi 21,9% MgO dan 54,3% CaCO₃. Namun MgO dari dolomit belum banyak dikaji sehingga penelitian ini dilakukan dengan tujuan untuk menganalisis pengaruh holding time kalsinasi terhadap fasa MgO yang disintesis. Metode sintesis MgO menggunakan metode Leaching yakni melarutkan dolomit dengan HCl dan distirer pada suhu 75°C selama 45 menit. Setelah itu dilakukan penyaringan yang hasil filtratnya ditambahkan amoniak hingga larutan mencapai pH 12 dan terbentuk endapan. Selanjutnya endapan tersebut disaring dan dikeringkan pada suhu 90°C selama 6 jam, dan dikalsinasi pada suhu 800°C dengan variasi holding time 4 jam, 8 jam, 12 jam, 16 jam, dan 20 jam. Serbuk hasil kalsinasi dikarakterisasi XRD dan FTIR. Hasil penelitian menunjukkan bahwa fasa utama MgO periclase terbentuk optimum pada holding time 8 jam pada suhu kalsinasi 800°C dan memiliki ukuran nanokristalin 20,12 nm. Hasil FTIR menunjukkan bahwa MgO hasil sintesis dengan holding time 8 jam memiliki gugus fungsi Mg-O, Mg-O-Mg, C=O, gugus alkena, dan H-O-H pada rentang bilangan gelombang 4000 cm^-1 – 500 cm^-1.

Kata kunci:MgO, leaching, holding time, sintesis.

Magnesium oxide (MgO) is a ceramic material that has potential in the medical and industrial fields, where MgO can be obtained from natural dolomite which has a composition of 21.9% MgO and 54.3% CaCO3. However, MgO from dolomite has not been studied much so that this study was conducted with the aim of analyzing the effect of the holding time of calcination on the synthesized MgO phase. The MgO synthesis method uses the Leaching method, which is dissolving dolomite with HCl and stirring it at 75 ° C for 45 minutes. After that, it is filtered where the results of the filtrate are added with ammonia until the solution reaches pH 12 and a precipitate is formed. Furthermore, the precipitate was filtered and dried at 90 ° C for 6 hours, and calcined at a temperature of 800 ° C with a variation of the holding time of 4 hours, 8 hours, 12 hours, 16 hours, and 20 hours. The calcined powder was characterized by XRD and FTIR. The results showed that the optimum MgO periclase main phase was formed at a holding time of 8 hours at a calcination temperature of 800 ° C and had a nanocrystalline size of 20.12 nm. FTIR results show that the MgO synthesized with a holding time of 8 hours has functional groups Mg-O, Mg-O-Mg, C = O, alkene groups, and H-O-H in the wave number range of 4000 cm^-1 - 500 cm^-1.

Keywords:MgO, leaching, holding time, synthesis.