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Dessy Amalia

R&D Centre for Mineral and Coal Technology

Author-ID : 3950073

Chemical Engineering, Chemistry & Bioengineering Chemistry Earth & Planetary Sciences Energy Engineering Environmental Science Materials Science & Nanotechnology

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POTENCY OF MAKING THE CHEMICAL MANGANESE DIOXIDE (CMD) FROM EAST NUSA TENGGARA PYROLUSITE Dessy Amalia; Azhari Azhari
Indonesian Mining Journal Vol 19, No 2 (2016): INDONESIAN MINING JOURNAL VOL. 19 NO. 2 June 2016
Publisher : Puslitbang tekMIRA

Chemical manganese dioxide has not yet commercially developed in Indonesia. It is supplied by import sector. The fact that Indonesia has manganese resources as many as 60,893,820 tons is inconsistent with above condition. Research on CMD making employed pyrolusite as the raw material with size of - 100+150 mesh. The material was then reacted with sulfuric acid 6% and various concentration of molasses as reductant from 10, 20, 30, 50 and 100 %. The manganese sulfate leachate was then purified using sodium hydroxide and then filtered to have a nonferrous manganese sulfate. The Mn was precipitated from manganese sulfate using sodium bicarbonate. The precipitated manganese carbonate was then calcined at 600°C by injecting the air at various flow rates (100, 200, 300, 400 cc/minute) and different calcination time (2, 3, 4 hours) to get manganese dioxide. The best extracted Mn reached 97.58% using 50% of molasses as a reductant. The precipitation of manganese carbonate had produced sodium carbonate as an impurity. The calcination had not yet changed the manganese carbonate into manganese dioxide due to extremely high calcination temperature.

ALTERING FERROUS SULPHATE TO SYNTHETIC GOETHITE Dessy Amalia; Yuhelda Dahlan; Suganal Suganal
Indonesian Mining Journal Vol 12, No 2 (2009): INDONESIAN MINING JOURNAL Vol. 12 No. 2 June 2009
Publisher : Puslitbang tekMIRA

Catalyst is required in any reaction. Coal liquefaction is one of the processes to have need of it. The most common catalyst used in the process is ferrous based catalyst. It is very influenced by pyrhotite, which may be occurred from goethite while goethite can be composed of any iron sources. The research had the use of ferrous sulphate as the main iron source, which was reacted with caustic soda. Parameters on molar ratio of the FeSO4.7H2O/NaOH were 0.2 and 0.33, reaction time applied were 3.5; 6.5 and 17.15 hours, oxygen flow rates of 100; 200; 300; 400 and 500 cc/minute were also observed. The best result was achieved at 0.2 molar ratio of the FeSO4.7H2O/NaOH within 6.5 hours by oxidation process that was containing pure goethite, while 100 cc/minute of oxygen rate was enough for the process to be happened.

PROCESSING ZIRCONIA THROUGH ZIRCON SAND SMELTING WITH NaOH AS A FLUX Yuhelda Yuhelda; Dessy Amalia; Enggan P. Nugraha
Indonesian Mining Journal Vol 19, No 1 (2016): INDONESIAN MINING JOURNAL Vol. 19 No. 1 February 2016
Publisher : Puslitbang tekMIRA

Zirconia had been made through smelting the zircon sand along with NaOH as a flux. The zircon sand as the smelter feed was taken from CV. Kurnia Alam Sejati mine at Palangkaraya, Middle Kalimantan. Major content of the zircon sand was 28.04% ZrO2 and SiO2 51.22% with several minor oxides such as 0.54% HfO2, 2.53% Fe2O3, 10.53% TiO2, 3.27% Al2O3 and less than 1% of alkali, alkaline earth and rare earth elements. In order to economizing the process, zircon sand upgrading was conducted prior to zirconia production. The upgrading process was conducted using several comprehensive equipments, consist of shaking table, magnetic separator and high tension separator (HTS).The upgraded sand contained 65.35% of ZrO2+HfO2 with 73.25% recovery, which was then used for smelting process at 650C for 2 hours using NaOH as a flux. The product was then leached with water and sulphuric acid then crystallized to get precipitated zirconium hydroxide. The precipitated product was calcined at 900C for 1 hour to get the zirconia and analyzed for its content. The zirconia content was 97.27% of ZrO2+HfO2 with 65.13% recovery.

PURIFICATION OF PREGNANT SOLUTION RESULTED FROM SPHALERITE CONCENTRATE EXTRACTION USING SULFATE ACID FOR ZINC OXYDE PRODUCTION Yuhelda Yuhelda; Dessy Amalia; Putri Dewi Novianti; Erlina Yustanti
Indonesian Mining Journal Vol 22, No 2 (2019): INDONESIAN MINING JOURNAL, Vol. 22 No. 2, October 2019
Publisher : Puslitbang tekMIRA

Purification of pregnant solution from sphalerite concentrate extraction using sulfate acid to produce zinc oxide was meant to prepare zinc oxide production technology utilizing existing internal sphalerite mineral raw material. The pregnant solution used to produce zinc oxide contains 29.84% zinc (Zn), with the biggest impurities iron (Fe) 11.68%. In order to obtain high purity zinc oxide, the pregnant solution should be recovered. It was done through solvent extraction method, in two process steps: extraction and stripping. The extraction was applying ligan bis di2ethylhexyle phosphate acid (D2EHPA) in toluene solvent, through ligan concentrate variation, pH and comparison of aqueous volume with organic volume (VA:Vo) and its excess. Stripping was carried out using sulphate acid through variation of concentration, pH and Vo:VA. To obtain optimum recovery, thus extraction and stripping should be carried out in many steps. The extractions and the strippings were calculated using McCabe Thiele diagram. Furthermore, zinc oxide was resulted from deposition and calcination of pure pregnant solution at temperature 700°C. Purification results show that the best extraction occurred at concentration D2EHPA 1 M, pH 3 and Vo:Va 2:1, through 4 step processes obtained recovery 97.50% with distribution coefficient 77.9; while the best stripping was obtained at H2SO4 concentration 2 M, VO:VA 2:1 through 3 step processes which obtained stripping percent 98.22% with stripping coefficient 1.51. On the other hand, zinc oxide solution resulted from purification was obtained Zn 93.31% in the form of hexagonal crystals (wurtzite).

PREPARATION OF NANO SILICA FROM SILICA SAND THROUGH ALKALI FUSION PROCESS Agus Wahyudi; Dessy Amalia; Sariman Sariman
Indonesian Mining Journal Vol 16, No 3 (2013): INDONESIAN MINING JOURNAL Vol. 16 No. 3 OCTOBER 2013
Publisher : Puslitbang tekMIRA

Silica (SiO2) materials play an important role for industries, especially those in micron or even nano-scale size. The later has better properties and improves its quality. Nano silica is applied widely in building material, notably as a mixture of concrete. The material is also promising to be developed into amorphous nano silicon for solar cell materials. Indonesia has a lot of silica sand resources and faces a challenge to increase its quality into high product such as nano silica. Synthesizing silica nano through alkali fusion is a process that includes using the particles along with sodium hydroxide at temperature of 400-1100 °C then recrystalizing the molecules to get materials in nano size. The recrystalizing process was conducted by water leaching and filtration. The derived nano particles (gel) ranged between 40-60 nm. TEM characterization showed that the products are homoge- neous, well dispersed and has specific surface area around 157 m2/g.

ALTERATION OF MONTMORILLONITE CLAY TO SOLID ACID CATALYST BY HEATING AND ACID SOAKING DESSY AMALIA; MUCHTAR AZIZ; Stefanus S. Cahyono; Isyatun Rodliyah
Indonesian Mining Journal Vol 12, No 3 (2009): INDONESIAN MINING JOURNAL Vol. 12 No. 3 October 2009
Publisher : Puslitbang tekMIRA

Commercial biodiesel production nowadays still uses sodium hydroxide solution as homogenous catalyst. This catalyst has some weaknesses, which cannot be reused and difficult on its separation from the product (methyl esther). Therefore, alternative catalyst is necessary to be sought to solve the problem and solid catalyst from clay has a possibility to be applied. Montmorilonite clay is widespread mineral in Indonesia and its layer structure is potential to be used as solid catalyst. The alteration processes consist of upgrading montmorillonite content followed by activation and esterification to review its performance. Previous activa- tion was carried out using aqueous sulphuric acid of 0.05; 0.5; 5 and 10 M and settled in each solution for two weeks. To obtain shorten activation time, modified method has been done with similar acid strength range but using preheating 60°C for 6 hours and settled within a week. Clay’s performance was observed by esterification reaction using Palm Fatty Acid Distillate (PFAD) of fried oil production waste as raw material. Its initial and final acid number were then reviewed. The conversion of PFAD to esther was measured from deviation of initial of final acid number. Previous method’s result of 2 weeks settlement showed maximum conversion of 91.6% at 5M acid strength of activation, while modified method reached maximum conversion only 67.63% at similar acid strength of activation. Both results were not yet resemble the 5M sulphuric acid solution as homogenous catalyst which is able to convert PFAD to esther as much as 98.73%. However, the method of 2 weeks settlement could be developed further to gain the optimum conversion.

Co-Authors AGUS Wahyudi Azhari Azhari Enggan P. Nugraha Erlina Yustanti Isyatun Rodliyah Muchtar Aziz Putri Dewi Novianti SARIMAN SARIMAN Stefanus S. Cahyono Suganal Suganal Yuhelda Dahlan Yuhelda Yuhelda Yuhelda Yuhelda

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