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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 : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol12.No2.2009.563

Abstract

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.
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 : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol22.No2.2019.1050

Abstract

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).